A day after giant Waratahs second-rower Will Skelton scorched all in his path to set up Bernard Foley's 76th minute try against the Brumbies and seal a home grand final for his teammates, Fairfax Media can reveal his 19-year-old brother has joined two-time Super Rugby champions the Chiefs.

At 145kg and 205cm, the younger Skelton was a valued member of the Waratahs' under-20s squad and was set to join the senior squad this coming pre-season to begin the challenging transition to Super Rugby.

But after representing Samoa in the junior world championships in New Zealand last month, Cameron Skelton was offered a package too good to pass up from Dave Rennie and the Chiefs.

Unlike Brumbies winger Henry Speight and centre Christian Leali'ifano, who both rejected overtures from Rennie in recent years, Skelton chose to carve out a career away from the spotlight on his older brother.

The move means the brothers, who are cousins of former All Black Brad Mika, will not have the chance to play together in coming years but may be playing against each other within one or two seasons.

The elder Skelton, meanwhile, was wrapped up in a historic NSW win on Saturday night

"We were under a lot of pressure and I guess that try sort of sealed the match," he said of his second-half run.

"But the boys were working hard off the ball and I heard a voice from Nard [Foley] and you give him the ball when he wants it. I was lucky enough to get the pass away and credit to Nard for being in the right place."

Skelton had made a handful of starts for NSW this season but in games in which coach Michael Cheika has been willing to take a more experimental approach to selection.

He is set to again be named as an impact player off the bench against the Crusaders, but after the success of his unexpected interchange with Kane Douglas - and not Jacques Potgieter - Cheika may be encouraged to try that tweak again.

After escaping with a penalty for a high shot on Brumbies No.9 Nic White, Skelton was apologetic.

''I've just got to get lower, full stop. I'm pretty tall but I can't use that as an excuse. You don't want to cost the team," he said.

"I'll try my best to work on that this week."