Wawrinka rolls in Finals opener

London, England (SportsNetwork.com) - Australian Open champion Stan Wawrinka was an easy round-robin winner Monday at the season-ending ATP World Tour Finals in London.

The third-seeded Swiss slugger mauled sixth-seeded former Wimbledon runner-up Tomas Berdych 6-1, 6-1 in a mere 58 minutes at the O2 Arena. Wawrinka (1-0) broke his Czech counterpart five times while holding his quality serve throughout on Day 2.

The world No. 4 Wawrinka had been stuck in a rut since losing in the U.S. Open quarterfinals, winning only one tour match since, but the Swiss played some of his best tennis of the year on Monday.

"I didn't expect to win that easy, for sure," said Wawrinka. "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."

Berdych is 0-1 in the four-player Group A, which also features world No. 1 star Novak Djokovic and eighth-seeded U.S. Open champion Marin Cilic. The Wimbledon titlist Djokovic is currently playing Cilic in Monday's other round- robin affair.

The three-time champion Djokovic is the reigning two-time Tour Finals champ, having beaten Rafael Nadal in last year's finale in London.

This week's other four-player group, or Group B, features second-seeded Roger Federer (1-0), fourth-seeded U.S. Open runner-up Kei Nishikori (1-0), fifth- seeded home favorite Andy Murray (0-1) and seventh-seeded Milos Raonic (0-1).

Nishikori, Raonic and Cilic are making their Tour Finals debuts this week.

On Tuesday, Federer will face Nishikori and Murray will battle Raonic.

Federer, who is making a record 13th consecutive appearance at the Tour Finals and has an outside chance of capturing the year-end top ranking, holds the record for the most titles at this tournament with six.

Round-robin action will be staged through Friday, followed by the semifinals on Saturday and lucrative final on Sunday.