Andy Murray was knocked out of the ATP European Open after losing 6-4 7-6 to Diego Schwartzman.
The Scot went into a 4-1 lead in the first set in Antwerp, but his Argentine opponent rallied to win five consecutive games to secure the first set.
The 29-year-old Schwartzman then went to break Murray at 2-2 to set himself up for a win, but Murray came back to make it 4-4, with hope of levelling.
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The match went to a tie-break, and Murray was able to save one match point until Schwartzman held his nerve to progress to the quarter-finals.
"I really like to play here," said Schwartzman, who set up a meeting with Brandon Nakashima of the USA in the last eight.
"It is a very special city for me because when I started to play my best tennis, I reached the finals here twice."
Murray had begun superbly, manipulating Schwartzman with aggressive groundstrokes to the back of the court to force the athletic Argentine to scramble around the court.
With Schwartzman unable to dominate with his strong return game, Murray quickly moved into a three game advantage.
But the 29-year-old grew into the encounter, able to force Murray off his power game and decisively taking the final five games of the first set to swing momentum his way.
Schwartzman broke again in the fifth game of the second set but was unable to secure victory, with Murray hitting back to take the encounter into a tie-break.
The former British number one saved one match point with a fine ace but was unable to take the match to a decider after driving a forehand long.
Murray had secured his last ATP Tour title in Antwerp in 2019 and showed signs of his best in outlasting Frances Tiafoe in a marathon round of 32 thriller.
Yet he was largely unable to re-capture such fluency against Schwartzman and bemoaned his own attitude on court after that crucial five game run of lost games to cede the first set.

British Andy Murray looks dejected during a singles match between British Murray and Argentinian Schwartzman, in the 1/8 finals of the European Open Tennis ATP tournament, in Antwerp

Image credit: Getty Images

“I didn’t make as many good decisions as I would have liked in the second set dealing with adversity,” Murray said.
“Mentally I was poor and my attitude was poor on the court.
"Sport is a results business. If you play well or poorly, it doesn't really matter if you lose the matches," Murray explained.
"You need to be winning and winning matches maybe when you're not playing your best, which I have done a few times these past few months, but certainly not as many as I would have liked.
"That's obviously what I want [in] the last few tournaments [of 2021]."
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