Maria Sharapova’s Grand Slam return after a 15-month doping ban ended in the US Open fourth round Sunday with the former world number one losing to Latvian 16th seed Anastasija Sevastova.

The 30-year-old Russian star, whose five Grand Slam titles include the 2006 US Open, fell 5-7, 6-4, 6-2 to Sevastova, who booked a Tuesday quarter-final matchup against American Sloane Stephens.

Sharapova, who returned to the tour in April after her suspension ended, had defeated world number two Simona Halep in the first round and was being spoken about as a potential title contender.

But despite pocketing the first set, her challenge fizzled out when she needed a medical timeout to treat a blister on her right hand.

She finished with 42 winners but 51 unforced errors against Sevastova, who also made the quarter-finals in 2016.

“Playing on Ashe stadium is an amazing atmosphere, every time. It’s fun to play here,” said 27-year-old Sevastova, who took victory on a fourth match point when Sharapova pushed a service return wide.

“The first set was very close. It could have gone either way. She played unbelievable throughout the first and second set and I just kept fighting, running for every ball.

“The emotions were high when I was 5-2 up in the final set. I wanted to close it so much.”