Sharp thinking by a ball kid on Thursday night enabled a quick throw in by Andrew Nabbout, which caught a 10-man Melbourne Victory cold.

Joey Champness then slid the ball past a stranded Lawrence Thomas for the Jets third in a 4-1 rout at McDonald Jones Stadium.

But to eagle-eyed commentators and fans, it was Nabbout receiving the ball further up the park than where it went out, which should have been spotted by match officials.

The Fox Sports match commentator noting: "And look at the ball boy - he's just bought them five metres. Well done son."

There was no suggestion the ball kid did anything wrong. But he looked good for the assist and received warm applause when his face popped up on the big screen.

It's the second time in three days that a ball boy has found himself at the centre of a football controversy.

During Tuesday night's FFA Cup Final, footage of Adelaide United's Michael Marrone manhandling a ball kid on the sidelines went viral. 

The boy appeared to turn his back on Marrone, who was trying to retrieve the ball for a quick throw in, bowling over the youngster in the process and sparking an all-in brawl.

Sydney FC clinched the Cup 2-1, while the Adelaide player was red carded and referred to the Disciplinary and Ethics Committee.

It was a much better night for the ball kid who was feted by the home side and taken on stage for the medal presentation.

Cases of ball kids co-opted by the home side to slow or speed the play have been reported overseas.

In May, Manchester City coach Pep Guardiola was caught deep in conversation with a ball boy on the touchline. In the Europa League final an injured Zlatan Ibrahimovic still did his bit by reportedly telling the kids to "go easy" in Manchester United's win over Ajax.

Sometimes they just like to get under the visiting team's skin. On New Year's Eve another pitchside partisan, stole Tim Cahill's thunder - and the corner flag - as the Melbourne City player rushed in for his famous boxing goal celebration in a match against Central Coast Mariners.