Football Federation Australia will on Monday investigate a potentially dangerous incident in the Sydney A-League derby where more than one hundred fans invaded the pitch with 10 minutes still left in the match.

In extraordinary scenes at a sold-out Allianz Stadium on Saturday night, Sydney FC supporters sitting in the Sky Blue fan section, The Cove, jumped the fence en masse upon captain Alex Brosque scoring the go-ahead goal in the 79th minute of their dramatic 3-2 victory over Western Sydney.

Dozens of people converged on the Sydney players celebrating the goal, and one fan even ran halfway down the field to tap Wanderers skipper Nikolai Topor-Stanley on the rear-end.

The Sydney Cricket Ground Trust can fine pitch invaders up to $5500 as well as ban them from the venue for 12 months.

Conviction notices from the NSW Police can also be issued for invading the playing field.

Due to the number of fans who took to the pitch, overwhelmed police and security guards at the venue were forced to simply usher people back over the fence instead of making arrests.

But with the incident broadcast on television, the Trust and police can examine footage and may choose to take action if patrons can be identified.

FFA confirmed that they would examine the incident on Monday once reports have come in from ground staff at Allianz Stadium and the match officials in charge.

Sydney FC have dismissed the incident as minor, but Wanderers coach Tony Popovic said the unauthorised access to the field posed a serious safety risk for players.

"Of course. You don't want to see that," said Popovic.

"That's why we have security at venues and you want to put a stop to that."

Sydney FC coach Graham Arnold suggested the pitch invasion was good for the game.

"Look, that just shows you how much it meant to our fans to beat West Sydney," he said.

The atmosphere at Allianz on Saturday was incredible, and the Sydney derby is now well and truly a showpiece event on the sporting calendar.

The crowd of 41,213 was the biggest regular-season crowd for any code at Allianz.

However, there were obvious concerns for the A-League in terms of crowd and player safety. Before kick-off, Wanderers fans threw flares, which had to be extinguished.

A child was among the horde of fans who invaded the pitch, and security measures may need to be bumped up for future derby encounters. - AAP