PARIS: Rafa Nadal's late-season resurgence continued at the ATP World Tour Finals when he beat wayward French Open champion Stanislas Wawrinka 6-3 6-2 to open his account on Monday.

The Spaniard, who has climbed back to fifth in the rankings after falling to 10th in a miserable summer, took advantage of an error-strewn Wawrinka display to move level with Andy Murray at the top of Ilie Nastase Group.

Nadal, back at the Tour Finals after missing out last year because of appendicitis surgery, dropped his opening service game to love but then broke Wawrinka's as the first nine points all went the way of the receiver.

Wawrinka blazed a forehand to fall 5-3 behind in the opener and Nadal wrapped up the set with an ace.

Nadal failed to convert any of the seven break points Wawrinka offered up at the start of the second set and then had to save two himself in the next game, one with a stunning lob.

World number four Wawrinka offered precious little resistance after that and his unforced error count climbed to 35 as Nadal raced to victory.

"I think I played well. I think I played a solid match. I had one bad game, the first one of the match. But then immediately I was playing well," Nadal told reporters.

"I had a good week of practice here. I think I played the way that I wanted to play. I played aggressive. I played with not many mistakes."

"But for the rest, all the shots worked well: backhand, forehand, good volleys, good smash, no missing the smashes today. So that's good."

The 14-times grand slam champion has won 14 of his 18 matches since a disappointing defeat in the U.S. Open third round by Fabio Fognini, reaching finals in Beijing and Basel as well as the semi-finals in Shanghai.

He will face Murray on Wednesday after the Briton also won his opening match against David Ferrer earlier on Monday.

Wawrinka will have to improve dramatically against Ferrer if he is to keep alive his hopes of emulating last year's showing when he lost to compatriot Roger Federer in the semi-finals.

"Was just a really bad day at the office. Many little things, as I said, that were not good today. It was a really bad match, bad behaviour from me in the second set.

"Hopefully I can put it back together and get ready for the next match."