Caroline Wozniacki beat Ekaterina Makarova 6-3, 6-3 Monday in the first round of the New Haven Open, her 18th consecutive victory at the tournament.
Wozniacki, the four-time defending champion, didn't get a bye this year after being seeded third behind Agnieszka Radwanska and Petra Kvitova.
She will face Sofia Arvidsson of Sweden in the second round. Arvidsson beat Melanie Oudin 6-4, 6-1.
Sara Errani rallied from being 2-5 down in the second set for a 6-4, 7-5 win over Bethanie Mattek-Sands.
Maria Kirilenko of Russia had an easier time, winning her first-round match 6-2, 6-2 over Shahar Peer of Israel.
Playing in only the third WTA main draw of her career, reigning NCAA champion Nicole Gibbs also won, beating fellow qualifier Alexa Glatch 6-4, 1-6, 6-4.