Wales coach Warren Gatland said Saturday's victory over rivals England was arguably the biggest result of his career.

Inspired by fly-half Dan Biggar's 23 points, Wales rallied from 22-12 down to clinch a crucial 28-25 Rugby World Cup victory against England at Twickenham.

Biggar's heroics helped Wales to back-to-back wins and top spot in the evenly-contested Pool A, which also includes Australia.

Given what is at stake in the group, with England likely needing a win over the Wallabies to reach the quarter-finals, Gatland was asked whether the win was the best of his career and he replied: "It is up there. There is nothing bigger than a World Cup and we all know how this pool is at the moment.

"This means a lot to me personally.

"Today was about courage. This game was about emotion and staying in the game. If you are still in the game at the end it can still go for you."

England had the chance to level the contest with two minutes remaining in London after the co-hosts were awarded a penalty.

However, instead of allowing Owen Farrell to kick at goal, Stuart Lancaster's England opted to kick for touch as they attempted to score a try, much to the surprise of Gatland.

"I thought they would have gone for goal and taken the draw. It was a brave call to me," the New Zealander added.

"We did a good job to stop that driving maul. Personally, I would have taken the three points."