London, Nov 11 (IANS): World No.1 Novak Djokovic breezed past US Open champion Marin Cilic in his first Group A match at the ATP World Tour Finals while third seed Stan Wawrinka of Switzerland also claimed a comfortable win over Czech Tomas Berdych here.

Djokovic, bidding to become year-end world No.1 and win the season finale for the third time in a row, recorded a 6-1, 6-1 win against the Finals debutant in 56 minutes Monday. It was his 58th match win of the season, reports Xinhua.

"Winning in straight sets helps a lot for the rest of the tournament," said Djokovic, who has extended his indoor winning streak to 28 matches. "But I'm going to try to win every match I play."

The 27-year-old Serb came through a 10-point second game, but never met any challenge thereafter.

"I felt that Novak played really, really solid," said Cilic. "I felt a little bit uncomfortable on the court, rusty, I felt that I was not hitting it clean. That's always difficult, especially against Novak, to get away with a win when you're not playing so good."

Wawrinka thrashed Czech Berdych with a identical scoreline in the Group A opener, needing just 58 minutes to beat the sixth seed.

"I didn't expect to win that easy," said Wawrinka. "But I was ready to play well. I had a great week of preparation. Even if the result wasn't there in Basel and Paris, I was feeling the ball really well on the practice court.

"When I feel good on the court, I'm ready to beat everybody. It's never easy, but you have to fight for it."

Berdych, who has now lost his past five matches against Wawrinka, committed 20 unforced errors and hit three double faults.

"Unfortunately, it was my worst match of the whole season and I kept it for the start here," said Berdych. "I didn't really feel anything right. I can just keep fighting and try to play good tennis."