Canadian Daniel Nestor and Serbian partner Nenad Zimonjic dropped a 6-3, 6-3 decision to Jesse Huta Galung of the Netherlands and Stephane Robert of France in the men's doubles final at the Barcelona Open on Sunday.
Huta Galung and Robert surprised the fifth-seeded pair in 54 minutes for their first career ATP title as a duo.
'Today was our worst match of the year.' - Daniel Nestor after doubles loss in Barcelona Open final
Nestor, who teamed with Zimonjic for victories here in 2009 and 2010, called the day "a disaster."
"It was not a good match from start to finish," Nestor said. "We made too many mistakes, That gave them confidence as the match went on and they played well.
"Today was our worst match of the year."
Nestor, from Toronto, reached the Barcelona final last year with former partner Robert Lindstedt of Sweden. They were beaten by Alexander Peya and Bruno Soares in three sets.
In this year's final, Nestor and Zimonjic lost serve three times in the opening set and never got on track against Huta Galung and Robert, who entered the main draw as lucky losers.
"In general we had a good week here, we won a couple of matches that we were in a position to lose," Nestor said. "We came back in the semifinal which was certainly our best performance of the week. But then there was today ... it would have been great to win a fifth title here but it didn't happen."
Nestor also won at Barcelona in 2004 and 2006 with former partner Mark Knowles of the Bahamas.
The Canadian has started the season with some impressive results with Zimonjic. They won at Sydney in January and reached the final in Dubai the following month.
They are assured a seeding and a first-round bye in the Madrid Masters next month. The extra time off will also allow Nestor to cross the Atlantic for some time with his family before returning for the big push through the clay season.
After Madrid, Nestor and Zimonjic plan to play at the Rome Masters and the French Open. Nestor has four career men's doubles titles at Roland Garros.
The Canadian also missed a chance to take over sole ownership of third place in the list of post-1968 Open era doubles title leaders. He remains tied with Australian Todd Woodbridge with 83 victories, behind Americans Mike Bryan (100) and Bob Bryan (98).