Oeiras, Portugal (AP)-Former U.S. Open champion Juan Martin del Potro, survived a scare to beat the Portuguese Pedro Sousa 6-2, 3-6, 6-3 in the first round of the Estoril Open on Tuesday.
Eighth-seeded Argentine, bringing his season debut on clay, broke his opponent's serve a third and seventh games to take the first half an hour.
But Del Potro is a double fault helped the game eight seconds Sousa, ranked 488th, the level of the game.
Argentina again double-faulted to lose his serve in the first game of the final set before breaking twice.
Del Potro is backwards in the rankings after undergoing wrist surgery almost a year ago.
Fifth-seeded Milos Raonic had a minor nuisance meeting eliminate Igor Andreev 6-4, 6-4, while sixth-seeded Thomaz Bellucci of Brazil beat Denmark Frederik Nielsen 7-5, 6-1.
In the women's competition, the fourth-seeded defending champion Anastasiya Sevastova came as Urszula Radwanska rallied to a 5-7, 7-6 (5), 6-1 victory.
Second-seeded Jarmila Gajdosova of Australia andthird-seeded Czech Klara Zakopalova advanced player after two consecutive victories, spread over Renata Voracova and Beatriz García Vidagany, respectively.
Eighth-seeded Greta Arn, the champion in 2007 when Hungary came through qualifying, beat Portugal Maria Joao Koehler 6-2, 3-6, 6-3.