Novak Djokovic missed out on a potential Monte Carlo Masters quarter-final against Rafael Nadal after losing to Austrian fifth seed Dominic Thiem.
Former world number one Djokovic, 30, was beaten 6-7 (2-7) 6-2 6-3 by Thiem in an engrossing last-16 match.
Thiem, 24, took his second match point to earn back-to-back wins over the 12-time Grand Slam champion.
World number one Nadal, 31, meets Russia’s Karen Khachanov in the last 16 later on Thursday.
Spain’s Nadal, who must win the tournament to prevent Roger Federer regaining the number one spot, is bidding for an 11th title in Monte Carlo.
Djokovic has slipped down the rankings to 13th as a result of an elbow injury which has restricted him to just four tournaments this year, but he showed glimpses of his best form against Thiem, who he described as a “top-three player in the world on clay”.
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The Serb saved three set points at 5-2 down in the first, breaking back to level at 5-5 and then taking the tie-break with his first set point.
However, he was outclassed in the second set and seemed to fade physically in the decider, Thiem claiming his first break point for 4-3 and then taking Djokovic’s serve again to win after almost two and a half hours.
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Thiem lost his first five meetings with Djokovic before beating him 7-6 (7-5) 6-3 6-0 in last year’s French Open.
Third seed Alexander Zverev progressed with a 6-4 4-6 6-4 win against fellow German Jan-Lennard Struff, while Belgian sixth seed David Goffin won 6-4 7-5 against Spain’s Roberto Bautista Agut.
Bautista Agut was given a code violation for accidently hitting a ballboy with a ball after going 4-1 down in the second set, recovering to save two match points and then winning four straight games to level at 5-5.
But Goffin broke again and served out the match at the third attempt to book a quarter-final against Bulgarian fourth seed Grigor Dimitrov, who won 4-6 6-3 6-4 against Germany’s Philipp Kohlschreiber.
Canada’s Milos Raonic pulled out of his last-16 match against second seed Marin Cilic with a knee injury.
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