Romanian Sorana Cirstea sent big-hitting fourth seed Elena Rybakina tumbling out of the US Open with a thrilling 6-3, 6-7(6), 6-4 victory on Friday to reach the fourth round at Flushing Meadows for the first time in her career.
Cirstea got off to a solid start, breaking former Wimbledon champion Rybakina in the fourth game of the opening set, and the seasoned world No. 30 continued to dictate points from the centre of the court while taking an early lead in the clash.
The 33-year-old, who had lost her previous two meetings with Moscow-born Kazakh Rybakina, pounced early in the second set but dropped serve immediately as her opponent found her range again with some blistering groundstrokes.
Australian Open runner-up Rybakina failed to make the most of two set points at 6-5 and squandered two more chances to draw level in the tie-break before getting the job done with a crosscourt winner, to the delight of the Louis Armstrong Stadium crowd.
But Cirstea composed herself to take charge of the decider and went up 4-1 before staving off a late comeback attempt by Rybakina and closing out the contest with a decisive late break after a double fault from her opponent.
Up next for Cirstea is a meeting with Swiss Belinda Bencic.
"It's one match at a time," Cirstea said. "At this stage in the tournament, everyone plays great and I'm glad that the work is paying off.
"Never stop believing in the things you do and the work you do because sooner or later if you put in the right energy... the things you want in life will come to you."
Coco Gauff won the final 10 games of her match against Elise Mertens, completing a 3-6, 6-3, 6-0 comeback and reaching the round of 16, where she will face Caroline Wozniacki on Sunday.
The American appeared in big trouble at the outset of the match as the Belgian smartly changed up the pace of her shots to frustrate the teenager, who was broken for a second time when her forehand went long on set point.
Mertens relished her opportunity to play the spoiler in front of a sold-out Arthur Ashe Stadium crowd firmly in Gauff's corner, quieting the increasingly tense fans with a shush finger after smacking winners.
After some exchanges of breaks early in the second set Gauff seized the momentum for good when she broke for a 4-3 lead, pumping her arms and pointing to her ear when her backhand winner leveled the contest at a set apiece.
The third set was all one-way traffic as Gauff's speedy defense, pinpoint serving and terrific play at the net overwhelmed former two-time quarterfinalist Mertens.
Next up for sixth seed Gauff is an enticing first meeting with returning veteran Wozniacki, who came from behind in similar fashion and by a similar score line earlier in the day to see off American Jennifer Brady 4-6, 6-3, 6-1.
