Sydney looked a potential championship contender when they went eight games unbeaten to start the season but then endured a festive season slump, taking just three points in six games and falling behind the league's top teams.

However, the Sky Blues are unbeaten since the Asian Cup break ended, taking 13 from a possible 15 points and remaining unbeaten since December 30.

That run has taken them to within a whisker of the top four. They are now sitting just a point behind fourth-placed Adelaide United and just a handful of points behind the top three, leaving Antonis to feel silverware is in their grasp.

"Definitely, if we keep working hard and grinding out the results every week, I definitely think we can [challenge for the title]," Antonis said at Sydney FC's post-match recovery session on Sunday morning.

"I think it's a real boost for the rest of the season. We've won two derbies and we drew the other one, all the boys are pumped up about that. But we can't get too carried away and big-headed, thinking it's too easy. We've just got to keep going until we get to the top."

After racing away to a 3-0 lead and spurning numerous chances to extend their league, the Sky Blues looked in complete control on their opponents' one-time fortress.

However, the Wanderers launched an incredible comeback, inspired by debutant Kerem Bulut, who followed up Iacopo La Rocca's goal with two of his own to bring the home side level with ample time to find a winner.

But it was Sydney who regained composure and coach Graham Arnold made the defining substitution in the 69th minute, taking Chris Naumoff off for Antonis. Seven minutes later, the 21-year-old charged forward to seize on a heavy touch from defender Brendan Hamill, dragging the ball with his right foot to his left and finishing expertly.

"The ball just came to me and I went from there. I didn't really get time to think too much about it. The game is just too intense out there," Antonis said. "It was a crazy feeling and very emotional. It's a huge thing, being able to score the winning goal in the derby."

"Especially playing away from home and in a big derby, actually scoring and getting the three points is hard to believe. I ran to the crowd because I was so excited. With seven goals on the night, it was a big score line. It was a pretty emotional night for all the players."

Despite some tense moments as the match wound to a close –- not least when Mickael Tavares was sent off in the 82nd minute – Antonis praised his teammate for digging deep to finish the job.

"It's always a tough game against Western Sydney and the intensity is always very high, which makes it hard when you're coming off the bench. But I think all the boys who came on for us did well. We stuck to our tasks well, even when we went down to 10 men," he said. "I think all the players knew they had to stick together.

"They didn't want to let another goal go in, everyone was defending for their lives and just desperately wanting to hold onto those three points. Everyone was delighted – and I was just really excited about beating them."