|Venue: Roland Garros, Paris Dates: 22 May to 5 June|
|Coverage: Live radio and text commentary on selected matches on BBC Radio 5 live sports extra, the BBC Sport website and app.|
Defending champion Stan Wawrinka recovered to beat Czech Lukas Rosol in the French Open first round.
Swiss Wawrinka, 31, who beat Novak Djokovic in last year's final, eventually came through 4-6 6-1 3-6 6-3 6-4 in three hours and 11 minutes.
Spain's Garbine Muguruza, last year's Wimbledon finalist, progressed with a 3-6 6-3 6-3 win over Anna Karolina Schmiedlova of Slovakia.
Play was delayed by more than two hours because of rain at Roland Garros.
Tournament organisers were already facing a backlog of matches after only four hours of play were possible on Sunday because of rain.
And Monday's wet conditions meant play could not start until 12:30 BST.
Who else is through?
Japan's fifth seed Kei Nishikori secured a 6-1 7-5 6-3 win over Simone Bolelli of Italy.
Nishikori finished off a first-round tie which had been suspended overnight with him leading 2-1 in the third set.
Eighth seed Milos Raonic is also through after defeating former top-10 player Janko Tipsarevic 6-3 6-2 7-6 (7-5).
Tipsarevic has had a terrible time with injury and illness and, now ranked 680, was making his first appearance at Roland Garros since 2013.
But former US Open champion Marin Cilic, the 10th seed from Croatia,fell at the first hurdle, losing 7-6 (7-4) 3-6 6-4 6-2 to Marco Trungelliti, a 26-year-old Argentine qualifier.
Radwanska races through
Second seed Agnieszka Radwanska sailed through, despatching Serbia's Bojana Jovanovski 6-0 6-2, while sixth seed Simona Halep, the 2014 final runner-up, dropped only two games in beating Japan's Nao Hibino.
Ukraine's Kateryna Bondarenko caused an upset by defeating seventh seed Roberta Vinci of Italy 6-1 6-3 while Tsvetana Pironkova of Bulgaria knocked out 16th seed Sara Errani, also from Italy, 6-3 6-2.
But perhaps the result of the day saw qualifier Veronica Cepede Royg of Paraguay - ranked 161 in the world - beat former Wimbledon runner-up Sabine Lisicki 6-2 6-2 in under an hour.
History for Turkey
Qualifier Cagla Buyukakcay beat Aliaksandra Sasnovich of Belarus to become the first Turkish woman in the Open era to reach the second round of a Grand Slam.
What about a roof over centre court?
The weather has dominated the first two days but there is not expected to be a roof over the main court, Philippe Chatrier, until 2020.
Residents have so far successfully blocked plans to renovate Roland Garros, with a verdict not due on the latest appeal until September.
Tournament director Guy Forget said: "When you go through two days like this you realise the importance of having a roof.
"I think it's a question of respect to the crowd and to the players that are waiting hours and hours in the lounges and in the locker rooms.
"While Wimbledon, Melbourne, and New York now have the new roof, we'll have to wait until 2020.
"Welcome to France. The red tape in France - it's a process.
"We asked for planning permission a long time ago. All we can do is monitor the situation and follow the due process."
There's a star in the house
British actor Tim Roth, star of Reservoir Dogs and more recently in a sporting role as former Fifa chief Sepp Blatter, was in the posh seats on Court Philippe Chatrier to watch defending champion Stan Wawrinka.
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