After witnessing one of the most astonishing away performances in the club's history - the win lifting Newcastle into the top six - a proud van Egmond declared his rejuvenated side had what it took to unsettle the competition's top sides.

"It's great for the team. We had a bit of rough trot there for a while and hadn't won a game away from home for over a year - we've now won two and it's a good feeling," he said.

"Everyone is selling something. I'm selling how we want to play and to close the deal is by winning.

"Now you get some results with it, the belief becomes a lot better (and) there's a lot more confidence within the group. It builds a platform.

"We're starting to gain some momentum and I think if we get into the finals we can cause a few headaches."

Newcastle stunned Sydney by scoring three times before half-time and withstanding a second half revival from their hosts before pulling away again late in the game.

Three ex-Sydney FC players - Jeremy Brockie (2), Ruben Zadkovich and Nikolai Topor-Stanley - supplied four of the goals with Ali Abbas nicking a fifth deep into injury time.

It's the first time the club has scored five goals in a match and they have now taken eight points from their past four matches to gatecrash the top six.

The Jets have set their sights on climbing further up the top six over the closing seven rounds.

"We know it's going to be even tougher in the run into the finals if we want to make the six and do something in the six," van Egmond said.

"You want to go in there with confidence. We have to keep our feet on the ground and keep our attitude right and who knows."