Andy Murray: I've shown I can beat the very best on a clay court

His second-round victory over the Argentine came in just 98 minutes and was his first-ever against a highly-rated clay court specialist at Roland Garros.

Murray admitted: "I still feel like I am getting questioned about why I am not doing better and I wanted to show I can beat the top clay court players.

"I was hitting shots that not too many guys can hit.

"Acasuso might not be a Federer or a Nadal but I showed I can play on clay. I wanted to show to myself I can do it.

"To win in straight sets, not lose my serve and break five or six times doesn't happen too often. It's not usual for a match to go as well as that.

"I'm very pleased, it was a great performance. I was very aggressive and my shot selection was great."

Murray even kept his cool when the umpire told him he would not get a let, despite accidentally hitting a linesman during a rally when he was pinned near the back wall.

"When I took the racquet back I felt I hit him very hard," he said. "I think it was on his head or his shoulder. The umpire said he couldn't do anything about it. That hadn't happened to me before."

The victory has given the No10 seed new confidence and set himself up for a clash with Spain's Nicolas Almagra, one of the most dangerous clay court players on the circuit. The 19-year-old has won two titles on the surface this year, beating David Nalbandian and Carlos Moya in those finals.

Murray said: "I put him in there with the top players on clay. I think he can play great.

"He's got a big serve, a big game. Doesn't move particularly well but he plays very aggressively and dominates the majority of his points. But I want to make the second week, that's my goal."

That match is tomorrow but second seed Rafael Nadal has not got the luxury of a day's rest as he will be back in action against France's Nicolas Devilder this afternoon, just 24 hours after beating Thomaz Bellucci 7-5, 6-3, 6-1 in the first round. Rain delays mean the Spaniard, chasing a fourth Roland Garros title in a row, needed three days to complete the match.

It was Nadal's 22nd victory in a row at Roland Garros and he said: "I don't think it's quite natural that all the guys who were to play their second match on Tuesday will play before me.

"That doesn't make sense. My opponent will have had two days of rest, and known about it in advance because of the weather forecast. I'm not complaining but I am saying there are things that are not logical about this."

Australian Open champion Novak Djokovic, the third seed, easily beat second round opponent Spaniard Miguel Angel Lopez Jaen 6-1,6-1, 6-3 in just 80 minutes and has sympathy for Nadal. He said: "It may be a little bit rough on him but I don't think the organisers did it on purpose."

Tomas Berdych became the highest men's seed to exit the French Open when he was beaten 6-3, 4-6 ,5-7, 6-3, 6-4 by local favourite Michael Llodra, who was roared to victory by fans.

Serbia's Ana Ivanovic, seeded two, needed only 55 minutes to batter Lucie Safarova of the Czech Republic 6-1, 6-2 and move into the third round, where she will face Denmark's Caroline Wozniacki.

Serena Williams, the fifth seed, and only former winner left in the draw after Justine Henin's retirement, had some problems before accounting for Mathilde Johannson, who served for the second set before the American came back to win 6-2, 7-5.

Russia's Anna Chakvetadze, the sixth seed, made the second round with a hard-fought 6-3, 5-7, 6-1 win over Nuria Llagostera Vives.

Vera Zvonareva powered past Stephanie Foretz, of France, 6-2, 6-1.