– Andy Murray escaped an upset, managing a 6-7 (3-7), 6-2, 6-2, 7-6 (7-3) defeat of Martin Klizan on Thursday to survive into the third round of the French Open.

Murray labored for more than three-and-a-half hours against a 50th-ranked opponent keen to inflict an upset on the top seed.

Murray will face another demanding test when he plays fellow former Grand Slam winner Juan Martin del Potro, who advanced when tearful opponent Nicolas Almagro was unable to go on with a knee injury, trailing 6-3, 3-6, 1-1.

Del Potro, who has a history of wrist surgeries and recuperations, sat down post-match on the Spaniard's courtside bench to comfort him. The Murray match will be a re-run of the Olympic gold medal clash from last August won by Del Potro.

Murray will need to lift his level after a poor clay run-up to the major if he is to fulfill his seeding.

"Physically I felt good," Murray said. "So that was very positive thing for me with a lot of the issues I have had this year to come through a match like that in that heat and feel good."

The Scot improved to 36-9 at Roland Garros. Among the things he railed at during his match was the Spidercam flying camera that particularly annoys him.

"I don't like it when it's in [view during] my ball toss," Murray said. "It happened three or four times in the first round where it was there. I asked for it to be moved. They moved it. Then it comes back.

"I just don't like it, it puts me off."

Other matches

• Fernando Verdasco beat Pierre-Hugues Herbert 6-3, 3-6, 4-6, 6-3, 6-3 to reach the third round and become only the third player to take part in at least 40 five-setters at Grand Slam tournaments in the Open era, which began in 1968.

The other two to reach 40 are Andre Agassi (41) and Lleyton Hewitt (45).

• Docked a point for smashing a pair of rackets, 18th-seeded Nick Kyrgios went from a set and a break up to a swift loss, ceding 16 of the last 19 games while losing to Kevin Anderson 5-7, 6-4, 6-1, 6-2.

• Bothered by her surgically repaired left wrist, 12th-seeded Madison Keys of the United States was upset in the second round by 290th-ranked qualifier Petra Martic of Croatia 3-6, 6-3, 6-1. Martic was the lowest-ranked woman in the second round at Roland Garros.

• Second-seeded Karolina Pliskova reached the third round for the first time after beating Ekaterina Alexandrova 6-2, 4-6, 6-3.