Dan Evans, the new British No 1, was knocked out of the Stockholm Open by Filip Krajinovic in the second round.
Evans, who had celebrated surpassing Kyle Edmund in the rankings with a first-round win over Bernard Tomic, fell 7-5 2-6 6-3 to the Serbian.
Krajinovic is ranked 17 places below the Briton and recovered from a disappointing second set to out-last Evans and reach the quarter-finals.
The Brit had started superbly by breaking Krajinovic in the opening game but the momentum began to change as his opponent fought his way into the match.
Murray back in Europe with victory
Andy Murray kicked off his final tournament of the 2019 ATP season with a 6-4 7-6 victory over Kimmer Coppejans at the European Open.
Eighth seed Evans was broken back before Krajinovic pounced again at the crucial moment to take the first set.
The 29-year-old Brit was a different proposition in the second set as he threatened the Krajinovic serve from the start, going on to secure a double break as he drew level in style.
But errors increasingly began to creep into Evans’ game and he paid a heavy price when he was broken to fall 3-1 behind the decider.
After saving another break point, Evans responded by breaking the Serbian back for 4-3, only to squander his serve again immediately and allow Krajinovic to serve out for the match.
Happy to be back! Punching my way through to the quarterfinals ! 馃Ц馃構馃挭馃徎馃幘馃榿馃檹馃徎馃З #happy #ATP #Antwerp #StanTheMan #tennis pic.twitter.com/CyEK7ZTR4e
— Stanislas Wawrinka (@stanwawrinka) October 16, 2019
Meanwhile, at the European Open in Antwerp, wildcard Stan Wawrinka got the better of Feliciano Lopez to reach the quarter-finals with a 6-7 (4-7) 6-4 7-6 (7-4) victory.
Wawrinka will next face Gilles Simon, who beat fellow Frenchman Jo-Wilfried Tsonga 6-4 7-5, while fifth seed Guido Pella also reached the last eight with a 7-5 7-5 win over Soonwoo Kwon.
Pella will encounter the victor of the contest between Ugo Humbert and David Goffin.