The 1-6, 6-3, 6-4 defeat of Caroline Wozniacki, the Danish third seed and former world number one, eliminated the last of the WTA Auckland Classic drawcards, a day after the exit of the two top seeds Serena and Venus Williams.
Czech Karolina Pliskova defeated Croatian teenager Ana Konjuh 6-2, 6-2 to reach the US Open semi-finals
Ana Konjuh, who has made it past the third round of a Grand Slam for the first time, next faces 10th-seeded Czech Karolina Pliskova in the US Open women's singles last eight