ESTORIL, Portugal (AP) -- Fifth-seeded Juan Martin del Potro beat Yuichi Sugita of Japan 6-1, 6-3 in the first round of the Estoril Open on Tuesday.
The former U.S. Open champion hit eight aces and broke Sugita four times to ease to the win in his clay-court debut for the season.
Del Potro, who won the Portuguese tournament in 2011 and 2012, will face American Ryan Harrison next after he beat Guillermo Garcia-Lopez 6-3, 2-6, 6-2.
American qualifier Bjorn Fratangelo upset sixth-seeded Joao Sousa 6-3, 6-4, and will face Taro Daniel of Japan after he beat Renzo Olivo 7-6 (2), 4-6, 7-5 in nearly three hours.
Nicolas Almagro also advanced after beating the eighth-seeded Benoit Paire 6-3, 6-2, while qualifier Joao Domingues outlasted Kyle Edmund 6-4, 3-6, 7-6 (2) and Carlos Berlocq beat Elias Ymer 7-5, 6-4.
On Wednesday, top-seeded Pablo Carreno Busta plays fellow Spaniard Tommy Robredo.