The Reds took a first half lead through Kristian Sarkies before Robert Cornthwaite’s sending off allowed Sydney to get back into the game through a sublime strike from Brendan Santalab.

FC then finished off United with goals from Steve Corica and Robbie Middleby in the second half to silence the record South Australian crowd.

The win takes Sydney four points clear of Adelaide in 5th spot with three games remaining and is a giant boost to their finals push.

“We need another good result,” said Kosmina. “We’ve got three games to get it but we don’t want to wait three games to get it.

“We want to win as many games as we can and we need to become a bit more ruthless in that regard.”

Sydney temporarily occupy third place on the ladder, level on points with second placed Queensland before Round 18 concludes on New Years Eve.

Kossie’s side face up to tough road trips away to Wellington and Queensland in the coming weeks before finishing off at home against Melbourne.

“We’ve had a good run and we’ve earned it. But we talked through the week that we need to start getting some results back to back,” added Kosmina.

“We need to go to Wellington now. We need to come to training Monday morning switched on because they’re a hard team especially away from home.

“Any of the top five teams are good enough to go on and win it. But there’s a lot of self belief in this squad.”