Tennis: Defending champion Nishikori advances to Memphis Open quarter-finals

Kei Nishikori of Japan hits a return shot to Ryan Harrison of the US in their Memphis Open tennis match at the Racquet Club of Memphis in Memphis, Tennessee, USA on Feb 11, 2015. Nishikori rallied to get past Harrison on Wednesday to book his qu
Kei Nishikori of Japan hits a return shot to Ryan Harrison of the US in their Memphis Open tennis match at the Racquet Club of Memphis in Memphis, Tennessee, USA on Feb 11, 2015. Nishikori rallied to get past Harrison on Wednesday to book his quarter-final spot at the ATP Memphis Open. -- PHOTO: EPA

MEMPHIS (AFP) - Two-time defending champion Kei Nishikori rallied to get past US qualifier Ryan Harrison on Wednesday to book his quarter-final spot at the ATP Memphis Open.

The Japanese top seed, who reached the quarter-finals of the Australian Open in January, gained a key early break in the third set and secured the 3-6, 6-3, 6-4 win on his fourth match point.

"It was a tight game but I'm really happy to win," the 25-year-old said.

"I think it's important to win something like this sometimes, it's good for confidence."

Nishikori, who enjoyed a first-round bye before opening his title defence against Harrison, said he feels like Memphis is "becoming my tournament".

Still, he said he will have to play better in the quarter-finals where he will face another American qualifier, Austin Krajicek.