Siem de Jong came off the bench to inspire Sydney FC to a 3-1 A-League win over Brisbane.

Out of action since a knee injury he suffered in January, De Jong had a hand in Sydney's second goal scored by Adam Le Fondre before sealing the win at Suncorp Stadium with a clever finish.

The victory puts pressure on table-topping Perth, with Sydney now six points behind them on the ladder as the Glory face third-placed Melbourne Victory on Saturday.

Sydney coach Steve Corica said getting the win before their rivals face off was a huge relief.

"It's vital, whichever way that game goes, we need to take care of our job first," Corica said. "We needed three points.

"It's been a difficult place to come here for us so to get the win was great.

Sydney, beaten 2-1 on their last trip to Brisbane, made the perfect start with defender Aaron Calver nodding home a Brandon O'Neill free kick with just 40 seconds on the clock.

That lead lasted until midway through the second-half when Roar interim coach Darren Davies brought on Nick D'Agostino and Henrique and switched to a 4-3-3 formation.

The change reaped an instant dividend with D'Agostino, fresh from his two-goal heroics for the Olyroos in midweek, swinging in a cross which French winger Eric Bautheac volleyed home from close range in the 68th minute.

But there was to be no memorable Roar comeback win this time around as De Jong and fellow substitute Reza Ghoochannej showed their class in the latter stages of the match.

De Jong made an immediate impact, slamming a shot off the post in the 77th minute after being found by Ghoochannejhad, with Adam Le Fondre tapping home the rebound for his 15th goal of the season.

The 30-year-old Dutchman -- who has been limited to just 11 appearances in an injury-affected campaign -- then scored the best goal of the match when he deceived Roar goalkeeper Jamie Young at his near post with a no-look finish from an acute angle.

Corica was thrilled for the former Ajax captain on his return to A-League action.

"He did the keeper, did it with his eyes," Corica said. "That's the quality he has."

Davies said Corica's ability to call on de Jong, Iranian international Ghoochannejhad and ex-Socceroo Josh Brillante off the bench told in the end against his team.

He also lamented conceding such a soft goal in the opening minute of the match.

"When they've got that quality coming off the bench, it's very powerful," he said. "But we can't do anything about that, we've got to focus on us. We'd worked all week to have a good start and that's out the window in 13 seconds.

"The decision for the free kick to commit to the foul was not good and then he's got a free header inside the six-yard box."

Sydney host Victory next week in a crucial clash for the top two positions while Brisbane are on the road against finals-chasing Melbourne City.