By Sonia Oxley

LONDON - One player smashed into a wall and others did the splits as damp grass at Wimbledon caused a series of dramatic skids and tumbles on Monday.

Frenchman Julien Benneteau had to call the trainer facing match point against fourth seed Novak Djokovic after crashing into the screen at the back of the court trying to chase a lob.

Former champion Maria Sharapova slipped twice and both times landed in an undignified heap on the ground, legs pointing in directions that only a very flexible person could achieve.

Even Roger Federer was not immune to the mischievous tricks of his favourite surface, getting wrong-footed in mid-rally before performing the sort of move usually attempted by top gymnasts.

"I don't know what's the cause but it was a little more slippery than I really expected it," said Djokovic, who beat Benneteau in four sets to reach the second round.

"But it's the same for both of us. It's the conditions. It's the new roof (on Centre Court). There's a lot of things involved," he told a news conference.

It was a dry day in London but Djokovic slid around the court as if playing on clay and Sharapova said the turf had slowed down so much in the past few years that players were having to approach it as they might the red dirt.

The Russian, who overcame Ukrainian Viktoriya Kutuzova, said the grass had seemed wetter than usual.

"The grass was damp, it was a little longer than on other courts and also it was the first match on the court," she said. Of all the day's acrobatics, Benneteau's accident was by far the most dramatic and not just because it was on match point.

After hurtling at the green screen, his racket flew out of his hands and he clutched his left knee in agony, eventually sitting down on a linesman's chair sporting grazes on his knees.

Djokovic walked over to ask him how he was before the trainer came on with some ice.

Clutching the cold pack to his knee, the Frenchman grimaced in pain but eventually stood up and limped over to baseline to take his serve.

Unleashing a powerful crosscourt winner, he kept himself in the match before succumbing two points later when he sent a forehand wide and left the court to a standing ovation.

"It was a funny situation," said Benneteau. -Reuters