Top seed Marin Cilic of Croatia survived three match points in a third-set tiebreaker against Igor Sijsling of the Netherlands to advance to the quarterfinals of the U.S. National Indoor Championships with a 7-6 (2), 3-6, 7-6 (7) victory Thursday.
Serena Williams carried her relentless form into the New Year with a 6-2, 6-2 victory over Alize Cornet on Tuesday at the Brisbane International, where Maria Sharapova withdrew and two other highly ranked players went out in the second round.
Caroline Wozniacki's first trip to the Brisbane International ended in a 2-6, 6-3, 7-6 (1) first-round loss to Kazakhstan qualifier Ksenia Pervak on Monday. She quickly followed up by dismissing speculation about an engagement to golf No. 1 Rory McIlroy.
Already qualified for the semifinals, top-seeded Caroline Wozniacki beat Slovakia's Daniela Hantuchova 3-6, 7-6 (4), 6-4 on Thursday to make it three wins from three at the season-ending Tournament of Champions.