Caroline Wozniacki eliminated eighth-seeded American Madison Keys 6-3, 6-4 Sunday to reach the US Open quarterfinals, her deepest run at a Grand Slam tournament in two years.
Wozniacki is a two-time runner-up at Flushing Meadows, but she is unseeded and ranked only 74th after a season filled with injuries and poor results.
She hadn't won a match at a major in 2016 until arriving in New York. She lost in the US Open finals in 2009 against Kim Clijsters and in 2014 against Serena Williams.
On Sunday, Wozniacki made only seven unforced errors, 26 fewer than Keys.