Wales' Liam Williams scores his team's third try against Tonga in Cardiff. Photo: Mike Egerton/PA via AP

CARDIFF – Wales coach Warren Gatland praised the impact of his bench players in their emphatic 74-24 November international victory over Tonga at the Millennium Stadium on Saturday after the Pacific islanders had briefly threatened an upset.

Tonga were level at 24-24 early in the second half having scored 21 unanswered points in the second quarter of the game.

But the introduction of the likes of scrumhalf Aled Davies, lock Cory Hill and replacement flyhalf Rhys Patchell saw Wales romp to an eighth Test win in a row.

“If you look at the game in segments, we started exceptionally well, we got ourselves into a bit of a hole then dug ourselves out of it with an outstanding second-half performance,” Gatland told reporters.

“I thought the bench was good again. As a collective group, they should be pretty proud of that.

“We have spoken in the past about trying to get momentum from the bench and they are really upping it. I thought they made a significant impact.”

Flyhalf Dan Biggar scored a try and kicked 14 points in a solid display with the boot, earning praise from his coach, while the equally impressive Patchell excelled when he came on.

Both are pushing Gareth Anscombe, who started the first two games of the November international series, for a starting place in next weekend’s home clash with South Africa.

“The pleasing thing is that all our 10s are playing well. We have been pleased with Gareth, and Rhys was excellent when he came on,” Gatland said.

“In a number of positions, we have some strength in depth and some real selection headaches.”

Gatland knows that the Springboks will supply arguably the side’s toughest test this month as they build towards the World Cup in Japan next year.

“They have gone back to traditional South African rugby, physical players, direct, it is going to be a real challenge for us,” New Zealander Gatland said.

“The good thing about where we are is that we are building our self-belief and confidence.

“We have had some good success over South Africa in recent years. It is important for us to hopefully build on that, and it will be nice to have a clean sweep in the autumn.”