The big defender struck just before half-time with skipper Travis Dodd wrapping up the points after the interval.

It was a miserable evening for the visitors who ended the match with 10 men after McFlynn was sent off for a second bookable offence.

It was an even and hard-fought first half before Ognenovski, in his 50th A-League game, headed a ball home in injury time and then Dodd made sure of the result with an opportunist goal in the 77th minute.

The Reds were the hungrier side but their job was made easier when McFlynn was red carded midway through the second half.

Adelaide’s first goal came about after Alemao was brought down by a Sydney defender as he cruised along the right side of the pitch.

Kristian Sarkies took the free kick about 30 metres out and Ognenovski was perfectly placed among a pack of players to head the ball home.

It was Ognenovski’s first goal for Adelaide United.

The home side’s next goal came in embarrassing circumstances for Beau Busch. He looked to clear a ball but his kick was smothered by Travis Dodd’s left boot.

Dodd got great purchase on the block and it flew forward and past a surprised Ivan Necevski.

The result puts Adelaide just three points behind top side Melbourne Victory while Sydney FC could drop out of the top four if Queensland Roar have a convincing win on Sunday.

It was a tight first half with both sides initially struggling to pierce the opposition’s defence.

About 21 minutes had passed before Adelaide United recorded a shot on goal while Mark Bridge provided Eugene Galekovic with his first challenge with an attempt from close range two minutes later.

For a while it appeared Sydney’s midfield rebound and Adelaide’s higher than normal turnover rate would see the visitors register the breakthrough score.

Sydney earned two corners in as many minutes while Steve Corica and John Aloisi were starting to weave through traffic.

But Adelaide had lifted in intensity too with Scott Jamieson making numerous crosses from the left flank while Alemao was an elusive opponent just outside the box.

The home side’s game gathered momentum and it wasn’t a surprise when they struck first through Ognenovski.

It was all Sydney in the early stages after the break with the visitors earning another two corners and Corica almost helping a ball through for the equaliser at the 51st minute.

But the Sky Blues’ hopes of victory were dented when a hobbling McFlynn was red-carded eight minutes later.

Down a man, it didn’t take long for Sydney FC to make a substitution with Alex Brosque coming off the bench to replace Mitchell Prentice.

United also made some changes and they continued to pressure the opposition. Sydney defended bravely before the Busch blunder further hurt its cause.

It opened the window for an all-out assault by United which peppered the goals in the final minutes of the clash.