Abu Dhabi - Andy Murray's return to action after a three-month injury lay-off ended in a straight sets defeat to France's Jo-Wilfried Tsonga at the Mudabala World Tennis Championship on Thursday.
The Wimbledon champion and world number four went down 7-5, 6-3 to 10th-ranked Tsonga on the opening day of the three-day exhibition tournament.
"The courts here are very fast and you have to react quickly," said 26-year-old Murray, who underwent back surgery in September.
"Jo was sharper than me today, he served very well.
"It's always good fun here. It's great preparation for the season as you have to play against the best in the world.
"I have played some of my best tennis in the Middle East."
Tsonga went into the match with an 8-1 career deficit in competitive matches.
Even though Thursday's clash was an exhibition meeting, the 28-year-old Frenchman was happy to have secured a rare triumph.
"It's not often I take two sets off Andy, even in practice," said the Frenchman who has been plagued in recent months by knee trouble.
"I want to give my best in 2014 and perform better than before."
The Mubabala Championship continues on Friday with world number one Rafael Nadal facing fellow Spaniard David Ferrer who beat Switzerland's Stanislas Wawrinka 7-5, 6-1 on Thursday.
Tsonga will face world number two Novak Djokovic also on Friday.