Defending champions the Chiefs scrambled to an unconvincing 22-16 win over the Melbourne Rebels on Saturday at Waikato Stadium, their first victory in four games.

After racing to a 19-0 lead in the opening 23 minutes, the Chiefs struggled for much of the remainder of the match as the Rebels fought back to being within a whisker of snatching an unlikely victory. There was only one try apiece, with victory ultimately determined by the boot of Gareth Anscombe who punished the Rebels with five penalties.

But it was not the performance the Chiefs wanted to boost morale after a winless three games on the road in which they lost to the Western Force then came from behind to snatch draws against the Cheetahs and Bulls.

There was no strong finish against the Rebels. Instead, they were fortunate to survive the closing minutes when they were reduced to 14 men with Pauliasi Manu yellow-carded and with the Rebels camped on their line.

Had the Rebels been a more experienced unit against the two-time champions, captain Scott Higginbotham felt they would have taken the game.

"We just panicked at the end. It's not good enough. It's a lack of experience I think," he said.

Anscombe, who proved to be the star of the Chiefs' show, was thrust into the central fly-half position after All Blacks pivot Aaron Cruden broke a thumb in South Africa, forcing him out of action for six weeks. The replacement No. 10, who directed the Chiefs with a more structured game than the mercurial Cruden, landed 17 points with the boot and set up the Chiefs' only try to Mike Fitzgerald.

With four penalties and the conversion, Anscombe had the Chiefs up 19-0 by the 23rd minute but it would be more than half an hour before they could score again as the Rebels came back at them. Jason Woodward landed two penalties before half-time and Japanese hooker Shota Horie scored immediately after the break with Woodward landing the conversion to narrow the gap to 19-13.

Repeated attempts by the Chiefs to cross the Rebels line for a second try were repelled by a stubborn defence and their only points in the second half came from a further Anscombe penalty. Woodward landed his third penalty with 15 minutes remaining to get the Rebels into bonus-point territory.

The win keeps the Chiefs at the head of the New Zealand conference while the Rebels, who have never won in New Zealand, remain at the bottom of the Australian conference.