US Open 2017: Caroline Wozniacki, Jo Wilfred Tsonga stunned in second round

New York: Two-time US Open runner-up Caroline Wozniacki's became the latest highly seeded women to make early exits at this year's tournament. The No. 5-seeded Wozniacki surprisingly lost to 40th-ranked Ekaterina Makarova 6-2, 6-7 (5), 6-1 in the second round.

Wozniacki had won all seven previous matches she had played against Makarova, whose best Grand Slam showing was a semifinal run at Flushing Meadows in 2014. Wozniacki is a former No. 1 who reached the US Open final in 2009 and 2014.

Her departure means four of the top seven women are out of the field just three days into the two-week tournament.

Wozniacki follows first-round losers No. 2 Simona Halep, No. 6 Angelique Kerber and No. 7 Johanna Konta on the way out of a bracket that already was missing 23-time major champion Serena Williams, who is off the tour while awaiting the birth of her first child.

Tsonga stunned by Canadian qualifier

Canadian teenager Denis Shapovalov stunned No. 8 seed Jo-Wilfried Tsonga 6-4, 6-4, 7-6 (3) at the US Open to reach the third round at a Grand Slam tournament for the first time.

The 18-year-old Shapovalov had to go through qualifying to get into the main draw in Flushing Meadows. He is almost exactly 14 years younger than Tsonga, the runner-up at the 2008 Australian Open.

Next up for Shapovalov is a match against Kyle Edmund of Britain. When they faced each other in the Davis Cup in February, Shapovalov was defaulted and fined $7,000 for hitting a ball in anger that struck the chair umpire in the face and broke a bone under his left eye.

Shapovalov's first major tournament came last month at Wimbledon, where he lost in the first round. He was the junior champion at the All England Club a year ago.