At the start of this long, long tennis season, Stanislas Wawrinka – or Stan, as he has subsequently become known in the official records – threatened to bust wide open the older order at the top of the game. He'd beaten Novak Djokovic and Tomas Berdych on his way to seeing off Rafael Nadal in the Australian Open final and looked to have finally shed the diffidence that comes with living in the shadow of Roger Federer.

On Monday, Switzerland's second-best player was back to his best, and he could not stop smiling in that quiet shy way of his. In beating Berdych for the fifth time in his career, Wawrinka made a perfect start in the first Group A match of the ATP World Tour Finals. Winning 6-1, 6-1, he even managed to bettered the ominous start Federer had made in Group B on Sunday when the world number two blitzed Milos Raonic in straight sets, also with a 6-1 opening set, although the Canadian rallied to take the second to a tie-break.

Tough six months

It was the most convincing of his 34 career victories over top 10 players and he is 7-1 this year but, as he pointed out: “I had, what, six wins against top 10 in the first three months of the year? Then I never played them again because I lose early in the tournament – so it was a tough six months after [Melbourne] .

“I think I showed from the beginning of the year, already from last year, that my level is there. When I feel good on the court, I’m ready to beat everybody. It’s never easy, but you have to fight for it. Normally when you play the top 10 guys, you are in the quarters or semi-finals of a tournament. So the confidence is there. I’m feeling great mentally.”

While Wawrinka changed perceptions of himself by breaking through for his first major, he also inspired others, notably the three debutants here: Raonic, Marin Cilic and Kei Nishikori.

“I was the first to win a grand slam outside the top four in so many years,” he said. “That showed it was possible. It gave a little bit confidence to the others.”

As for Federer, who is enjoying a resurgence even the 17-slam champion might not have anticipated a year ago, Wawrinka doesn't think the grind of the season will inconvenience the 33-year-old father of four ahead of their Davis Cup partnership, in which they almost certainly will play both the singles and doubles.

Unpredictable hardcourt

On the unpredictable hardcourt of the O2 Arena, Wawrinka hit a peak that left Berdych helpless, beating him in under an hour. It was as embarrassing for Berdych – who took only two games off Novak Djokovic in China last month – as it was encouraging for Wawrinka.

He served well, and tormented the Czech world No7 with his crosscourt backhand and slice-and-chip, which injected doubt into Berdych’s game, a sometimes fragile commodity under pressure.

“Unfortunately, it was my worst match of the whole season,” Berdych acknowledged.

Guardian Service