Nishikori's medal dreams ended by Del Potro

Kei Nishikori saw his Olympic medal dreams dashed by Argentina's Juan Martin del Potro as the Japanese 15th seed lost their quarter-final clash 6-4, 7-6 (7/4) on Thursday.

Nishikori was bidding to become the first Japanese player to reach the semi-finals of the Olympic singles since Ichiya Kumagai won a silver medal at the 1920 Games in Antwerp.

But del Potro, who will play Wimbledon champion Roger Federer for a place in the final, was just too powerful for the 22-year-old in windy conditions on Court One.

"It was tough conditions for both of us. It was windy. I wasn't making many first serves so it was tough for me to play my best game," Nishikori said.

"But he was playing well. He didn't miss much and he was really steady on the baseline."

Despite the disappointment of missing out on a medal, Nishikori admitted he enjoyed the experience much more than his last taste of the Olympics in Beijing four years ago.

"It's a good experience," he said. "The last time I played in Beijing I lost in the first round.

"I felt a lot of pressure and I couldn't play my tennis but now I have more confidence."

Nishikori had shocked Spanish fourth seed David Ferrer less than 24 hours earlier in a third round tie finished under the floodlit Centre Court after being moved indoors due to fading light.

But the Florida-based star just didn't have the energy to subdue the big-hitting del Potro, who also beat Nishikori in the Wimbledon fourth round last month.

Del Potro broke in the second game of the match, but Nishikori replied with a break of his own in the next game.

That set the stage for a gruelling eighth game which saw Nishikori stave off two break points before del Potro finally broke at the third attempt.

Even then Nishikori wouldn't surrender and he saved a set point before breaking back. But del Potro took the set with another break in the next game.

Del Potro broke in the second game of second set, but his nerve failed him as he served for the match at 5-3 and two double-faults gifted Nishikori a lifeline.

That set up a tie-break and del Potro finally took advantage after racing into a 4/1 lead that prove too much for Nishikori to overcome.