Concerns that the injury which forced the Japanese to retire from the Halle semi-finals would scupper his Wimbledon campaign surfaced midway through the fifth set when he had to get his stricken left calf re-strapped while leading 3-0.

Despite being in some discomfort, fifth-seeded Nishikori kept going for three hours and 22 minutes to win his second successive five-set marathon against Bolelli at Wimbledon after the pair went the distance in the third round last year.

"It's a little bit sore from last week but it's getting better and it wasn't easy to play for three hours but it should be okay for the next match," Nishikori said moments after walking off court.

Nishikori, who last year became the first Asian man to contest a grand slam singles final when he finished runner-up at the U.S. Open, will have 48 hours to regain his fitness before facing Colombian Santiago Giraldo.

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