Roger Federer surprisingly dropped the first set against little-known Malek Jaziri before putting the Tunisian upstart in his place with a 5-7 6-0 6-2 win to reach the second round of the Dubai Championships.
Jaziri, ranked 128th in the world, had not played a match on the ATP Tour for six months but that did not stop him snatching the first set from the 17-times grand slam champion.
After watching Swiss Federer squander three break points in the opening set, Jaziri could barely believe his eyes when his more celebrated opponent slapped the ball into the net to go a break down at 5-6.
Jaziri, 29, made sure his bragging rights did not end there as he took the first set with a rip-roaring backhand down the line passing shot winner that left Federer flat-footed and the fans sensing a night-time upset.
However, if Jaziri started to wonder what it would feel like to beat a champion like Federer, those dreams were brutally snuffed out as the second seed exacted revenge by racing through the next two sets.
On a relatively low-key opening day, seventh seed Andreas Seppi beat Frenchman Paul-Henri Mathieu 6-3 7-5 and Russian eighth seed Mikhail Youzhny overcame Slovenia's Blaz Kavcic 1-6 6-1 6-3.
Top seed Novak Djokovic was in action on day one with his brother Marko but their doubles adventure ended in round one. They were beaten 4-6 6-3 10-4 by Nikolay Davydenko and Dick Norman.