Yulia Putintseva produced an impressive upset, knocking defending champion Coco Gauff out of the Cincinnati Open in the second round.

The 29-year-old rallied over three sets to hold off Gauff's comeback with a 6-4 2-6 6-4 win in just under two hours.

Putintseva immediately set the tone by breaking the American's serve twice in the opening three games, and though Gauff pulled back to level things at 4-4, the Kazakh got another vital break to take the first set.

The world number two came out on a mission in the second though, piecing together a three-game winning streak as she managed to force a decider.

And it looked like Gauff had found her stride when she took a 4-2 lead, but Putintseva won the last four games in a row to turn the tide and set up a meeting with Paula Badosa in the next round.

Data Debrief: Gauff falls short again

After a disappointing Olympic debut, Gauff made an early exit from the Canadian Open, and she has been relegated to another early exit here.

She was looking to become just the second player to win consecutive titles here, but instead, she struggled once again, making nine double faults against a flawless opponent.

Meanwhile, Putintseva is playing her first tournament since Wimbledon, where she knocked out Iga Swiatek en route to the fourth round. Before this year, she had never progressed past the first round in Cincinnati. 

Now, she is only the fourth player in the past four decades ranked outside the WTA's top 20 to claim wins over the top two on multiple surfaces in a season.