British number one Cameron Norrie could not build on a one-set advantage against Denmark's Holger Rune as he was eliminated from the Stockholm Open quarter-finals.
The Wimbledon semi-finalist had already beaten Rune three times this year and won a tight first set between the pair, but he ultimately slumped to a 7-6[4] 3-6 3-6 defeat in just over two hours.
An error-strewn fifth game from the Danish 19-year-old saw Norrie earn the first break of the contest before recovering from a 30-0 deficit to hold, but Rune turned up the heat soon after.
The teenager broke back for 4-4 after holding to love - the first of three consecutive service games in which he would do so - but Norrie got the upper-hand in the tie-break to clinch the first set.
Rune meant business in the second set, though, breaking in the third game before firing in two consecutive aces to hold for 3-1 straight after, and he levelled the match after just 36 minutes in that set.
The aces kept on flying in for Rune, but Norrie held firm and won his opening three service games before his Scandinavian counterpart earned the vital break in the eighth game for 5-3.
Serving for a place in the semi-finals, Rune produced an 11th ace of the day to bring up match point, which he duly converted to set up a semi-final tie with Australia's Alex de Minaur.
For Norrie - currently ranked world number 14 - the defeat is another blow to his chances of qualifying for the ATP Finals, which begin on November 13 in Turin.
Compatriot Dan Evans faced a challenging test of his own against Felix Auger-Aliassime as he sought to make the semi-finals of the European Open in Antwerp, and he gave the youngster a good run for his money before ultimately bowing out.
The 32-year-old has been the centre of controversy this week following his Davis Cup outburst, and he lost 6-4 6-7[4] 2-6 to Auger-Aliassime in two hours and 40 minutes.
Auger-Aliassime flew out of the blocks with two aces in his opening service game, but three winners from Evans saw him break for a 2-1 lead in the third game of the match.
The British number two remained relatively untroubled on his way to a first-set triumph, but Auger-Aliassime then squandered three break-point opportunities in game four of the second set.
Both men would proceed to power through their remaining service games before a tie-break, which Auger-Aliassime got the upper hand in to force a deciding third set after winning 86% of points on his first serve in the second.
While Evans held to love in the first game, the relentlessness of Auger-Aliassime soon came to the fore, as he missed two break opportunities before taking his third for a 2-1 lead.
Another break would come the Canadian's way in the seventh game as unforced errors proved costly for Evans, who needed to break his opponent's serve for just the second time in the match to get the job done.
After bringing up two match points, the 22-year-old beat Evans with a passing forehand at the net to book his spot in the semi-finals against Richard Gasquet of France.
