Sigmund scored the match-winner against Perth Glory in similar fashion in December and Wednesday's goal was just as important to the Phoenix's top six aspirations before Ifill completed his comeback from a groin injury to provide the icing on the cake.

The win – the Phoenix's second against Sydney at Westpac Stadium this season – saw them leapfrog the Sky Blues to take fourth spot.

The first half was a tale of two penalties as Brett Emerton and Daniel traded spot kicks before Dani Sanchez chipped Sydney keeper Liam Reddy to give the Phoenix a 2-1 lead at the break.

A soft goal to Bruno Cazarine, who was also denied by the woodwork twice, got Sydney back on level terms until Sigmund rose above the Sky Blues defence to head home in the 78th minute then Ifill wrapped things up in his own inimitable style.

There was barely a dull moment in the opening 45 minutes, although it was the Phoenix who had the better of the early chances with Sanchez curling a free-kick just wide of Reddy's goal in the fourth minute then hitting the side netting four minutes later.

Mark Bridge had an excellent chance to opening the scoring in the 15th minute when he got on the end of a poor Sigmund clearance but Tony Warner made an excellent one-handed save to deny the Sydney striker.

Despite both teams playing with good width and creating chances the first two goals came from the penalty spot as first Phoenix midfielder Vince Lia then Sydney defender Jamie Coyne handled in the box.

Emerton blasted his spot kick past Warner in the 16th minute to give Sydney the lead then nine minutes later Daniel calmly slotted his past Reddy to level the scores.

Sydney should have taken the lead in the 32nd minute when Coyne's pin-point through ball set up Cazarine but his shot came back off the post.

Reddy was then forced into a double save at the other end as Sanchez then Leo Bertos unleashed.

The deadlock was eventually broken in the 42nd minute when Sydney coughed up possession and Daniel's long-range cross picked out Sanchez who chipped Reddy to notch his fourth of the season.

The Phoenix then had to endure a nervous finish to the half as Manny Muscat saw an attempted clearance come back off the underside of Warner's crossbar before the woodwork denied Cazarine again, as he latched onto the rebound.

The start to the second half was less frenetic with neither goalkeeper unduly troubled.

Ifill replaced Chris Greenacre on the hour mark but it was Sydney – who had earlier brought on Rhyan Grant for Jamie Coyne and Juho Makela for Dimitri Petratos – who got the equaliser thanks to some average goalkeeping from Warner.

Emerton made a burst from midfield and put the Brazilian clear.

The Phoenix keeper was flatfooted and although he got a hand to Cazarine's shot the ball trickled over the line.

The Phoenix pressed hard for the winner and were duly rewarded with a corner which Bertos swung into the box and Sigmund latched on to.

But Sydney weren't done and Warner was called into action again but this time held firmly onto Cazarine's fierce shot.

Reddy though had no such luck against his former team-mate Ifill.