O'Halloran was one of the unsung heroes who helped fire the Giants to a four-point victory over Geelong in what was their first victory in four games.
The stats sheet will show the 23-year-old finished with a small haul of ten disposals and one clearance, but his impact on the contest goes beyond how many times he touched the ball.
O'Halloran was handed the mighty task of restricting five-time All-Australian defender Tom Stewart at their Geelong fortress, and restrict he did.
Stewart pulled off 13 intercept possessions to cause trouble for Gold Coast's forwards in their match before GWS.
Against O'Halloran, the Cats star notched seven.
Defender Connor Idun played a similar role on Jeremy Cameron, keeping the inaugural Giant and one-time Coleman Medallist to just one goal.
"It can be scary. They're stars of the comp but when you're given that role, you go in with an understanding that the coaches have full belief that you can get that done," O'Halloran told AAP.
"You have to take confidence out of that - that you are more than capable of doing that.
"It's just understanding what needs to be done. I might not necessarily be getting 20, 30 touches. It's 'try and minimise that impact that Tom can have'."
GWS players embrace Xavier O'Halloran (2L) after he kicked a goal in the win over Geelong. (Julian Smith/AAP PHOTOS)
O'Halloran has become a familiar face across the GWS midfield and forward line, but he has yet to cement himself in the starting line-up.
After featuring in last season's finals series as the substitute, the versatile Melbourne product was next in line when veteran Callan Ward was sidelined for two months with a shoulder injury earlier this year.
He was subsequently dropped for the Sydney derby with skipper Toby Greene's return from suspension, before Kingsley called on his services again after two strong showings in the VFL.
Asked if playing a defensive forward role could become a feature of his game, O'Halloran says he'll play whatever role the coach asks of him - the same mentality that goes across the entire Giants squad.
"We get given a role on the weekend, no matter where you're playing," O'Halloran said.
"I had one on the weekend. It doesn't necessarily happen every week but if that gives myself the best chance of playing and the best chance of us winning then I'm more than happy to do it.
"It could be given to anyone. It could be Tom Green who plays every game and has a tremendous impact for us.
"We're all quite good in that ... if we are asked to do something, then everyone will do it."
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