Roger Federer’s comeback from injury ended in the quarter-finals of the Qatar Open after he was beaten by Nikoloz Basilashvili.
On Wednesday, Federer, 39, overcame Britain's Dan Evans on his return to court after 14 months out with a knee problem.
But the 20-time Grand Slam champion was unable to secure a second win in as many days as Basilashvili completed a 3-6 6-1 7-5 victory.
Basilashvili, ranked 42 in the world, saved a match point against a weary-looking Federer in the 10th game of the deciding set, before breaking his Swiss opponent in the ensuing game, and seeing out the match in one hour and 50 minutes.
“It is unbelievable because he is one of the greatest of all time,” said Georgian Basilashvili, 29, following his last-eight triumph. “To play him means so much to me.
“I am very happy he came back to play, and to win against him is a dream come true.
“He was always my idol, and I am sure he is to many tennis players and fans, so I am unbelievably happy.”
Basilashvili will play Taylor Fritz for a place in the final in Doha following the American's 5-7 6-3 7-5 win against Denis Shapovalov.
“I’m happy I am back on the tour,” said Federer on the ATP website. “I’m pleased I came here to Doha. So it’s really, really a positive return for me. I’m really happy.
“I come from so far away that I’m actually happy that I was able to play back-to-back three-set matches against top players. That’s an important step forward to me.”
Andrey Rublev became the first player in ATP history to receive back-to-back walkovers as he reached the semi-finals without hitting a ball.
Richard Gasquet withdrew from his second-round clash against Rublev following a leg injury before Marton Fucsovics was forced to pull out of their last-eight meeting with a back problem.
Rublev will face Roberto Bautista Agut after the Spaniard knocked out top seed Dominic Thiem 7-6 (3) 2-6 6-4.
At Marseille's Open 13 Provence, top seed Daniil Medvedev secured a 6-2 6-4 victory against Egor Gerasimov to reach the quarter-finals, while qualifier Arthur Rinderknech booked his first ATP Tour quarter-final match after beating Spaniard Alejandro Davidovich Fokina 3-6 6-1 6-2.
Second seed Stefanos Tsitsipas, bidding to secure a hat-trick of Marseille titles, saw off Lucas Pouille 6-2 6-3 to set up a clash with Pierre-Hugues Herbert following the Frenchman's 6-3 6-4 victory against Cameron Norrie.
At the Chile Open in Santiago, qualifier Juan Pablo Varillas knocked out seventh seed Federico Coria 6-4 7-6 (2) to reach the quarter-finals, while Colombian Daniel Elahi Galan saw off third seed Pablo Andujar 6-1 7-6 (7) to reach the last eight.
