KUALA LUMPUR, Malaysia (AP) -- Juan Monaco of Argentina reached the quarterfinals in his Malaysian Open debut but fellow seeds Alexandr Dolgopolov of Ukraine and Feliciano Lopez of Spain lost on Thursday.
Second-seeded Monaco defeated Taiwanese wild card Jimmy Wang 6-4, 7-5. The Argentine responded to losing his serve three times by breaking Wang five times.
''I started really bad and missed a lot of balls,'' Dolgopolov said. ''I came back in the second set, but it was an up and down match.''
Dutchman Igor Sijsling upset No. 5 Lopez, 7-6 (0), 7-6 (2). They played impeccably on serve with 11 aces each and no break points conceded, but Lopez struggles in both tiebreaks.