Ben Mowen was the ultimate super sub, sparking a second-half revival as the Tuggeranong Vikings held off a gallant challenge from Royals to maintain their runaway lead in the John I Dent Cup.

The ACT skipper shrugged off a gruelling week in Wallabies camp to help the Vikings rebound from a seven-point half-time deficit to win 36-24 at Viking Park yesterday.

''I was carrying a bit of fatigue out of the camp this week, but that's fine, it enables you to get a bit more of a fitness hit in the game,'' Mowen said. ''The club games are a little bit more open so you get a bit more running.''

Run he did.

After spending the opening half on the bench, the hard-charging No.8 got his hands on plenty of ball.

Mowen was held up over the try-line, and was on track for a barnstorming 70-metre effort until he was cut down by a desperate cover tackle from a Royals winger.

There was even an audacious clearing kick - something he'd never get away with under Jake White's watch.

''Jake would cut my leg off if I did that at the Brumbies, so I've got to have a crack at these things in club land,'' Mowen laughed.

''There's some great footballers in the Canberra comp.

''The Brumbies guys started their allegiances early on in the year and we're all enjoying that rivalry at training.''

All Brumbies players not on the injured list turned out in the John I Dent Cup yesterday.

How many games Mowen plays for the Vikings depends on whether he's retained in the Wallabies squad when it's amended tomorrow for the next batch of training ahead of the Rugby Championship.

The Royals were on the verge of causing a major upset until the Vikings scored twice in the final 10 minutes to break the deadlock, to the frustration of Royals coach Craig Lesberg.

''A few errors and ill-discipline proved pretty costly, but it was nice, we were in it for a vast majority of the game,'' Lesberg said.

''It was certainly our intention to be nice and physical and put some pressure on at the breakdown, I think we achieved that.''

John I Dent Cup: TUGGERANONG VIKINGS 36 bt ROYALS 24 at Viking Park; GUNGAHLIN 35 bt UNI-NORTHS 0 at Nicholls; WESTS 52 bt EASTS 7 at Jamison Oval.