American Bethanie Mattek-Sands was one of only four opening-round winners Tuesday, as rain continues to wreak havoc at the hardcourt Malaysian Open tennis event.

The wild card Mattek-Sands upset sixth-seeded Croat Donna Vekic 6-3, 4-6, 6-2.

Third-seeded Anastasia Pavlyuchenkova was leading fellow Russian Vera Dushevina 2-6, 6-3, 2-1 when play was called for the day, as six matches were either suspended or postponed because of inclement weather.

Fifth-seeded Japanese Misaki Doi leveled Italian Alberta Brianti 6-2, 6-3, while Austrian qualifier Patricia Mayr-Achleitner handled France's Claire Feuerstein 6-3, 6-4 and Czech Karolina Pliskova doused Aussie Casey Dellacqua 6-3, 6-2.

Fourth-seeded Japanese Ayumi Morita was leading Turk Cagla Buyukakcay 5-1 when play was stopped.

Rain wiped out all of Monday's schedule in Kuala Lumpur.

Former world No. 1 Caroline Wozniacki is the top seed here and will face Chinese qualifier Qiang Wang on Wednesday.

This week's second seed, Taipei's Hsieh Su-Wei, beat Croat Petra Martic in last year's finale.