Britain's Andy Murray fell to American Sebastian Korda in the Gijon Open quarterfinals on Friday.
Korda, ranked 47, won through 6-4, 1-6, 6-1 against former world number one Murray, now ranked 48, in two hours and 27 minutes.
Wildcard Murray was playing his first tournament since September's Laver Cup, but after rallying in the second set the 35-year-old was unable to maintain the momentum in the third.
Korda, 22, advances to meet France's Arthur Rinderknech who saved nine match points before ousting second seed Pablo Carreno Busta, the last Spaniard in the tournament, 4-6, 6-3, 7-6 (16).
Rinderknech staved off two match points on serve at 4-5 in the third set, and a further seven in the third-set tie-break, before sealing victory on his sixth match point after just over three-hours in northern Spain.
Earlier, Austrian Dominic Thiem continued his quest for his first title since the 2020 US Open when he eased past fourth seed Francisco Cerundolo of Argentina 6-4, 6-3.
The 29-year-old next plays top seed Andrey Rublev who dispatched fifth seeded American Tommy Paul 7-5, 6-3 in 87 minutes.
Rublev, who triumphed in Marseille, Dubai and Belgrade earlier this season, has boosted his chances of qualifying for the ATP Finals.
