Del Potro ousts Karlovic

Paris - Argentina's Juan Martin del Potro needed four sets and more than three hours to beat big-serving Croat Ivo Karlovic 6-7 (7), 6-3, 7-5, 6-4 in the first round of the French Open on Monday.

The 25th-seeded Del Potro was a semi-finalist at Roland Garros in 2009 - the year he won the U.S. Open - but didn't compete at the tournament last year after undergoing wrist surgery.

The right-handed Argentine made the most of Karlovic's 42 unforced errors and will next play Blaz Kavcic of Slovenia. He could then face tournament co-favorite Novak Djokovic in the third round.