Britain's Emma Raducanu was outclassed by world number five Zheng Qinwen in the quarter-finals at Queen's.
She showed flashes of her quality but ultimately fell 6-2 6-4 to the Olympic champion in front of a packed crowd.
Raducanu took a medical timeout after the first set, having struggled with back spasms over the past few months.
She started the better in the second set and led 3-0 but could not keep Zheng at bay as the Chinese rediscovered her big-hitting form.
Raducanu was given a true physical test by Zheng, but it was another defeat that showed the gap between the British number one and the world's very best.
Zheng will face either third seed Emma Navarro or Amanda Anisimova for place in the final.
Qualifier Tatjana Maria earlier stunned former Wimbledon winner Elena Rybakina to set up a semi-final meeting with Australian Open champion Madison Keys.
Maria, 37, beat Rybakina 6-4 7-6 (7-4), while Keys fought back to see off Russia's Diana Shnaider 2-6 6-3 6-4.
There was reason for Raducanu to be confident against Zheng, who is still finding her feet on the grass court and has a serve that can waver when under pressure.
Raducanu had also made relatively serene progress through her first two matches, dropping just eight games across four sets.
But, as Raducanu found against Iga Swiatek in Melbourne and Paris, and Coco Gauff in Italy, there is a different, consistent level needed to beat the players for who winning is a habit.
In an edgy start, Raducanu put pressure on Zheng's serve while saving break points in her own games.
But Zheng broke through at the seventh attempt, a blistering backhand down the line silencing the crowd, who had earlier voiced their displeasure after Zheng had to change her shoes midway through the game.
Raducanu kept up the pressure, creating an immediate break-back opportunity, but Zheng's huge groundstrokes kept her at bay, and a rushed forehand into the net handed the top seed the first set.
Raducanu left court for a medical timeout on her back, having struggled with back spasms before and after Roland Garros, but took advantage as Zheng's first serve all but disappeared.
With the wind picking up, Raducanu produced a series of ruthless returns to Zheng's second serve and quickly found herself a double break up thanks to some strong serving.
But Zheng wrestled a break back and upped her intensity when needed, creeping forward to attack Raducanu's serve. A double fault handed Zheng the break back and she reeled off four games in a row to close out the match.
Despite the loss, there will be enough for Raducanu to be confident she can perform well on the grass - but she will know there is still a gap to be bridged when it comes to challenging the very best.
Earlier, world number 86 Maria used her slice-heavy style of play to outfox 11th-ranked Rybakina.
Maria broke the Kazakh for the first time in the competition on her way to taking the first set, before the pair traded early breaks in the second.
Former Wimbledon semi-finalist Maria was unable to serve out the match at 5-4 but showed no signs of nerves in the tie-break to cement her place in the last four.
She will now face Keys, who battled back from a messy first set to beat rising talent Shnaider.
A below-par Keys succumbed to the clean ball-striking of Shnaider, who broke serve twice on her way to taking the opening set.
But back came the American, who made 12 unforced errors in the opening set, as she upped her level considerably, with a sole break enough to wrap up the decider.