Argentina's Juan Martin del Potro had a day to forget in the semifinals of the Western and Southern Open in Cincinnati, losing to Novak Djokovic 6-3, 6-2.

Del Potro had upset the Serbian world No. 2 when the two squared off for the bronze medal earlier this month at the London Olympics, but he repeatedly squandered his chances against his opponent's serve on Saturday.

"I had I think six break point in all the match and I didn't take any one. Against Novak or the top players, if you don't take your opportunities, you will lose for sure," the Argentine said in the post-match press conference.

"I think he play much better than me today basically in the important moments or the break points. He was too good for me."

Del Potro also said the wrist injury he suffered earlier in the week bothered him on Saturday.

"It's pain like bother me all the time, and I don't want risk too much. I have experience in wrist problems, and I would like to take time to fix this little problem."

Del Potro missed most of the 2010 season after undergoing surgery on his right wrist. He injured his left wrist this week.

Djokovic will next take on world No. 1 Roger Federer - a 7-6 (7-4), 6-3 winner Saturday afternoon over fellow Swiss Stanislas Wawrinka - in Sunday's final.

The Western and Southern Open is one of nine ATP World Tour Masters 1000 events and a key tune-up for the U.S. Open, which gets underway later this month. EFE