Top seed Rafael Nadal and world number two suffered a 6-0 6-1 thrashing at the hands of Russia's Mikhail Youzhny in the final of the Chennai Open.
Youzhny has a good record against Nadal on hard courts
The Spaniard was clearly affected by his four-hour semi-final against compatriot Carlos Moya.
He lost all three service games in the opening set and called for medical attention at 4-1 down in the second.
World number 19 Youzhny closed out the match after just 58 minutes on court for the fourth title of his career.
Nadal quickly dismissed fears his comprehensive defeat was because of an injury sustained in his marathon match against Moya on Saturday, the longest three-set match on the ATP Tour in 15 years.
"There is nothing wrong with me - I called the trainer because I was feeling tired," said the 21-year-old.
"Mikhail played unbelievable tennis and deserved to win.
"I will now go to Melbourne and practise for a week and hopefully I will be at my best at the [Australian] Open.
"The good thing is I leave this tournament without any injury. It has been a good start to the year for me. I have had good practice."
Youzhny admitted his win owed much to coming up against an off-key Nadal.
"This victory is a present from Rafael," said Youzhny, who has beaten Nadal in four of their seven encounters on hard courts.
"I did not think it would be so easy. I thought he would come back strongly in the second set but once I broke him in the fourth game, I knew I only had to ensure I did not make mistakes.
"I improved with every match in this tournament and I hope I continue the same way at the Australian Open."