Australian Open champion Stanislas Wawrinka returned to form with a 58-minute 6-1 6-1 thrashing of Tomas Berdych at the ATP World Tour Finals on Monday.

The world number four has been stuck in a rut since losing in the U.S. Open quarter-finals, winning only one tour match since, but the Swiss looked back to his best as he opened proceedings in Group A at the O2 Arena. “I didn’t expect to win that easy, for sure,” Wawrinka, who made the semi-finals here last year on his tournament debut, told reporters. “But I was ready to play well. “I had a great week of preparation. Today, the start of the match was really important. That changed it completely.”

He came within a point of winning the opening set 6-0 but was thwarted by a Berdych ace. His opponent could not turn the tide, however, and Wawrinka wrapped up victory before the hour mark.

It was the most one-sided contest at the season-ender since it arrived in London in 2009, with Berdych managing one game less than Rafa Nadal got off Wawrinka’s Davis Cup team mate Roger Federer in 2011.

In early doubles play, third seeds Alexander Peya (Austria) and Bruno Soares Czech Tomas Berdych said he was facing “mission impossible” after being on the end of a 6-1 6-1 thrashing by Stanislas Wawrinka at the ATP World Tour Finals on Monday.

‘Worst possible position’

The 29-year-old will now almost certainly have to beat world number one Novak Djokovic, and U.S. Open champion Marin Cilic, to have any chance of reaching the semi-finals. “I’m in the worst possible situation that I can ever be,” Berdych told reporters. “I’m going to face Marin or Novak and the only chance to qualify is to beat them, it’s almost a mission impossible.”

Berdych, a semi-finalist in London three years ago, can take some comfort from the fact that the previous four times he has qualified for the tournament, he also lost his opening match.

His record in his second round-robin match is 4-0 though. “I’ve just got to come up with some better tennis,” he said. “Unfortunately, it was my worst match of the whole season today, and I kept it for the start here in the World Tour Finals. So that’s not the best one at the start,” he said. “My game is about hitting the ball nice, clean, then you can create something,” said the former Wimbledon runner-up. “But I didn’t have that today. I hit so many frames,” Berdych added.