Marin Cilic is the first man through to the Wimbledon quarter-finals.

The Croatian ninth seed advanced when Japanese fifth seed Kei Nishikori retired with a rib injury while trailing 6-1 5-1 in their fourth-round match on Monday.

In a repeat of their 2014 US Open final, which Cilic won to secure his first and only grand slam title to date, Nishikori managed to win just seven points in the opening set.

He continued to struggle before calling it quits as Cilic closed to within a game of a two-set advantage.

Cilic will play either seven-time champion Roger Federer or American Steve Johnson on Wednesday for a spot in the semi-finals.