Doha - Defending champion David Ferrer crashed out in the first round of the Qatar Open on Tuesday, beaten in three sets by Ukraine's Ilya Marchenko, ranked number 94 in the world.
Ferrer, the number four seed, struggled throughout, losing his serve in the very first game and eventually going down 7-6, 3-6, 2-6 in an eventful clash lasting over two and a quarter hours.
"Of course I am disappointed because I lost in the first round," said Ferrer, the world number seven.
He was playing with a new racquet but said this was not the reason for his loss.
"I am happy with the racquet. The problem is not the racquet, it's my serve."
For Marchenko, the result represented the best victory of his career.
Before Tuesday's game he had never beaten anyone in the top 10.
More remarkably it was the first time that Marchenko had even won a set against a top 10 player.
"It was a fantastic day for me, I am really happy with the performance," said the 28-year-old.
"It's a fantastic way to start the season."
Despite losing the first set, Marchenko, hitting booming forehands and backhands from the baseline throughout, had served for the set at 5-4.
However, he squandered his chance and Ferrer clawed his way back in typical fashion, eventually taking the tie-break 10-8 in a set lasting one hour and eight minutes.
But he was immediately broken in the second set by Marchenko, who this time held on and then powered through the final set to claim a famous victory.
Despite double-faulting three times in the final game, Marchenko eventually closed the game out to claim a second round clash on Wednesday against Russia's Teymuraz Gabashvili.
Ferrer won the Qatar Open last year -- one of five World Tour singles titles he took during 2015 -- beating Tomas Berdych in straight sets in the final.
Earlier on Tuesday, Berdych, who is this year's number three seed, beat another Ukrainian, Sergiy Stakhovsky in straight sets, 7-5, 6-4.
The Czech said he was "feeling good" after his victory.
Rafael Nadal, the number two seed, plays later on Tuesday against compatriot Pablo Carreno Busta.