It was a remarkable achievement for a team which had previously played just one season in the National Soccer League, following the club’s formation in 2003.

The Reds went on to lose a tight Preliminary Final to Central Coast Mariners, ending their hopes of becoming the first A-League Champions and claiming an impressive double.

Here is the Adelaide team that started that day and what has happened to them since...

Daniel Beltrame

Aussie goalkeeper Daniel Beltrame played 14 times for Adelaide in his first season with the club, helping the Reds win the inaugural A-League Premiership in 2006.

Beltrame, who also won two National Soccer League titles with Wollongong Wolves, is best remembered for his two stunning saves in a penalty shootout against Newcastle Jets, which sent Adelaide through to the 2007 Grand Final.

The Reds were thumped 6-0 by Melbourne Victory in the final, after Adelaide captain Ross Aloisi received an early red card.

Beltrame, now 41, played one more season for The Reds before hanging up his boots in 2008.

Adam Van Dommele

Adam van Dommele was just 21 when Adelaide won the first A-League Premiership 11 years ago.

The full back played 19 times for the Reds in the 2005/06 campaign, following a brief spell at English club Hartlepool United.

Van Dommele’s opportunities at Adelaide were limited the following season, when he played just five times before moving to National Premier League side South Melbourne FC.

Van Dommele signed for MetroStars in 2009 and has played for the Adelaide-based club ever since. 

The full back, now 32, is one of the senior players for Metro and was made vice-captain at the club in 2011.

Kristian Rees

After representing Adelaide in the National Soccer League and the A-League, Rees went on to play for Wellington Phoenix and Gold Coast United. 

The imposing centre half was instrumental for the Gold Coast, making 72 appearances for the Queensland side before their A-League licence was revoked in 2012.

Rees made the tough decision not to play for the remainder of the 2011/12 campaign, electing to put his family first, with no guarantees that the Gold Coast would still exist the following season.

The centre half, now 37, continued to support former United owner Clive Palmer, who repaid Rees’ loyalty by employing him in a variety of roles.

Rees returned to football in 2013, joining NPL Queensland side Palm Beach.

The Aussie spent two years with the Sharks, helping them win the Championship in 2014, before retiring a year later.

Angelo Costanzo

Costanzo joined Adelaide at the start of the inaugural A-League season in 2005, following spells with Adelaide City and Marconi Stallions.

The defender spent four successful years at Adelaide, racking up 72 league appearances for the Reds. 

Costanzo, now 40, was named in Adelaide’s team of the decade in 2013, after helping the Reds reach the Finals Series on three separate occasions.

In 2009, Costanzo signed for Newcastle Jets, where he played one season before retiring from the professional game. The defender was also capped six times by Australia.

Michael Valkanis

The current Melbourne City head coach spent a remarkable 13 years at Adelaide, first as a player, then a captain, then a coach.

Valkanis, a commanding defender in his playing days, represented Adelaide for six seasons, helping the Reds win the inaugural A-League Premiership and reach the 2008 AFC Champions League final, before retiring in 2009.

A year later, Valkanis joined Adelaide’s coaching staff before taking up the role of assistant manager in 2012. He was then promoted to caretaker manager following the resignation of manager John Kosmina in 2013.

Valkanis guided the Reds to the Finals Series that campaign, however they were eliminated by Brisbane Roar at the first stage.

In 2016, Valkanis said goodbye to Adelaide, leaving the coaching setup after the Reds won a historic Premiership and Championship double.

Later that year, Valkanis was appointed assistant manager at Melbourne City. He then took on the role of head coach following the resignation of John Van't Schip.

Richie Alagich

Alagich waved an emotional farewell to Adelaide in 2008, following the Reds’ goalless draw with Chinese side Changchun Yatai, which secured qualification from their Asian Champions League group.

The defender, who made 121 appearances for the Reds between 2003 and 2008, had already made the decision to retire from the professional game ahead of the crucial clash.

Following spells with West Adelaide and Brisbane Strikers, Alagich signed for the newly-formed Adelaide in 2003 before playing in their first ever game at the Hindmarsh Stadium.

That night, Alagich set up Carl Veart for the only goal of the game, as Adeaide overcame Brisbane Strikers 1-0.

Alagich, now 43, quickly became a popular figure with the Adelaide supporters and in 2013 he was named in the Reds’ team of the decade.

He had one unsuccessful season with the Reds women's team imeediately after he hung up his boots before joining Football Federation SA  where he's now Skills & Acquisition Coach.

Ross Aloisi

Combative midfielder Ross Aloisi captained Adelaide in the inaugural A-League season, following spells in Switzerland, France, Austria and Italy.

Aloisi made 60 A-League appearances for the Reds between 2005 and 2007, earning him a place in Adelaide’s team of the decade in 2013.

However, his time with the club ended sourly, after the midfielder was sent off in the 6-0 Grand Final defeat to Melbourne Victory in 2007.

The following season, Aloisi signed for Wellington Phoenix, where he made 13 league appearances before retiring in 2008.

Since then, Aloisi, now 43, has gone into coaching. The former A-League midfielder was the senior assistant coach with the Westfield Matildas during their run to the quarter-finals of the 2015 FIFA Women’s World Cup.

Later that year, Aloisi was appointed assistant coach at Brisbane Roar, where he joined his older brother and head coach John.

Last month, Aloisi received a four-game A-League ban, after an alleged tunnel bust up with Adelaide assistant coach Jacobo Ramallo in the aftermath of Brisbane’s game against the Reds.

Travis Dodd

Adelaide-born Travis Dodd will always be remembered as one of the Reds’ most successful captains.

After signing for Adelaide in 2005, Dodd went on to become the first United player to play 100 games for the club.

In 2008, Dodd was made captain of Adelaide and became the first skipper to lead an Australian club to an AFC Champions League final.

Dodd also earned two caps for Australia and became the first indigenous player to score a goal for the Socceroos in a game against Kuwait in 2006.

The attacking midfielder spent three years at Perth Glory between 2011 and 2014, making 48 appearances before retiring at the age of 34 due to ongoing injury concerns.

Last year, Dodds returned to Adelaide, taking up a part-time coaching role at Gleeson College to help young boys and girls play soccer.

He also signed a contract with Metrostars and has done commentary work with Fox Sports.

Fernando Rech

The Brazilian forward also made it into Adelaide’s team of the decade in 2013, following two prolific years at the club.

Prior to joining Adelaide, Rech spent three years at Brisbane Strikers, where he won the Johnny Warren Medal, which is awarded to the best player in the Australian top flight, in 2002.

Rech was 31 when he joined Adelaide in 2005 but was still a key player as the Reds reached back-to-back finals series between 2005 and 2007.

The creative playmaker, now 43, retired from the professional game after that and he has kept a low profile ever since.

Carl Veart

Veart will always be remembered as the player who scored Adelaide United’s first ever goal back in 2003, in a 1-0 victory over Brisbane Strikers.

The versatile forward also had spells in England with Sheffield United, Crystal Palace and Millwall, before joining Adelaide.

Veart played his final game for the Reds in 2007 in a AFC Champions League game against Vietnamese side Gach Dong Tam Long, when he received a warm send-off  Hindmarsh Stadium.

Shortly after his retirement, Veart, now 46, joined the Adelaide coaching team before moving on to be the head coach at Football Federation South Australia's National Training Centre.

Shengqing Qu

The former Chinese international first played for Adelaide in 2004, after signing on loan from Shanghai Shenhua.

Qu spent two years with the Reds and was an instrumental figure, scoring seven goals in his first spell at the club, helping Adelaide to the inaugural A-League Premiership.

The popular striker, now 41, signed permanently for the Reds in 2006, following a brief loan spell at Chinese side Nanjing Yoyo.

However his second stint with the club was cut short due to injuries, and he declined a new contract for 2007/8, returning to China and a brief spell coaching Guangzhou Evergrande reserves.

John Kosmina (Manager)

The former Socceroos skipper was appointed Adelaide United’s first manager in 2003, after coaching Brisbane Strikers and Newcastle Breakers.

After guiding the Reds to back-to-back Finals Series and winning the inaugural A-League Premiership, Kosmina was sacked by the club following a humbling 6-0 Grand Final defeat to Melbourne Victory – in which Kosmina was caught in a sideline scuffle with Victory's Kevin Muscat.

Later that year, Kosmina landed the job at Sydney FC, however a poor run of form towards the end of the 2008/09 campaign saw the Sky Blues fail to make the Finals Series - resulting in Kosmina’s dismissal.

In 2011, Kosmina returned to Adelaide United as caretaker manager to replace Dutchman Rini Coolen.

At the end of the 2011/12 season, Kosmina was rewarded with a permanent contract, and appeared on track to guide the club to yet another Finals Series.

However, Kosmina stepped down from his position due to “a lack of trust” with his board.

Last year, Kosmina, now 60, signed a three-year deal with Brisbane City in the National Premier League- a position he still holds to this day, as well as being an analyst on Fox Sports.