Roger Federer suffered a shock defeat to world No 116 Evgeny Donskoy at the Dubai Tennis Championships.
In an unbelievable turn of events, the 18-time Grand Slam champion was defeated by his widely unknown second-round opponent 3-6 6-7 6-7.
Donskoy produced a remarkably relaxed display, seemingly unaware of the enormity of the occasion, as he ousted Federer in style.
The Russian, who has a career-high ranking of 65, which he reached in 2008, saved three match points before winning the second set tie-break 9-7.
And the third set tie-break epitomised a match of wildly unpredictable momentum, Federer moving into a 5-1 lead before Donskoy reeled off six straight points to take the match, and - with it - the greatest result of his career.
Fresh from his remarkable Australian Open win earlier this year, former world No 1 Federer was subdued in defeat.
"I just never really got going tonight and sort of felt heavy," said Federer, who was chasing a record eighth title at the Dubai Championships.
"But look, those matches happen frequently, where you just got to somehow find a way to come through.
"Tonight I was convinced that, if I came through, I was going to feel better tomorrow. I came [to Dubai] early, I was perfectly prepared, it's just a tough loss tonight.
"So many chances, it was crazy. There are no excuses there.
"I just think it's still the beginning of the comeback and I've got to take the positives out of playing again a tournament where I feel I'm quite healthy, and I'm happy I got over the injury I sustained at the Australian Open."
Donskoy said: "I surprised everyone today, I think whoever wins against Roger surprises himself.
"I can say it's a dream come true but I don't like this because you always want to win, even if it's Roger."
Donskoy will next face seventh seed Lucas Pouille in the quarter-finals.
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