World number one Novak Djokovic crashed out of the Rolex Monte Carlo Masters following a shock last-16 defeat to Italy's Lorenzo Musetti.
he 22-time grand slam champion surrendered a one-set and 4-2 lead to lose 4-6 7-5 6-4 in a rain-interrupted match in Monaco.
After clinching the opener, Djokovic struggled to find his best level in the windy conditions on Court Rainier III.
The 35-year-old lost serve seven times before wet weather forced the players off with the score at 1-1 and him leading 40-30 in the third game of the deciding set.
Following the resumption of play, the tie remained on serve until the seventh game of the final set when 21-year-old Musetti secured what proved to be the decisive break.
Top seed Djokovic, who won the tournament in 2013 and 2015, doggedly saved three match points before eventually succumbing to defeat to the world number 21 in a thrilling contest lasting two hours and 54 minutes.
"I am struggling not to cry," Musetti said in his on-court interview, according to atptour.com.
"It is an emotional win because it was a really long match. Three-hour match and suspended by rain. It was not easy conditions because it was a little bit windy and cold - not like we used to play in the recent days.
"I am really proud of myself. I am struggling not to cry because it is a dream for me. Beating Novak is something remarkable for me."
Musetti's reward for a first career victory over the Serbian is a quarter-final showdown with compatriot Jannik Sinner.
Sinner battled back to beat Poland's Hubert Hurkacz 3-6 7-6 (6) 6-1 earlier on Thursday.
Meanwhile, reigning champion Stefanos Tsitsipas, who is bidding for a third successive title in Monte Carlo, overcame Chile's Nicolas Jarry 6-3 6-4.
The Greek second seed will take on Taylor Fritz in the last eight following the American's 4-6 6-4 6-1 comeback victory over Czech player Jiri Lehecka.
World number four Casper Ruud - the 2022 French Open and US Open finalist - suffered elimination at the hands of Germany's Jan-Lennard Struff, losing 6-1 7-6 (6).
Elsewhere, Denmark's Holger Rune was awarded a walkover victory against injured 2021 Wimbledon runner-up Matteo Berrettini, while Andrey Rublev beat fellow Russian Karen Khachanov 7-6 (4) 6-2.
Daniil Medvedev later set up a quarter-final meeting with Rune by saving two match points in a dramatic 3-6 7-5 7-6 (7) victory over Alexander Zverev.