Rafael Nadal showed his class in the key moments to beat John Isner 6-4 7-6 (7-0) and book his place in the semi-finals of the China Open.

Isner thrashed Leonardo Mayer to reach the last eight and was typically strong on serve as he made life tough for the world number one on Friday.

However, Nadal broke late in the first set to seize the advantage and then wrapped up the match by dominating a tie-break.

Grigor Dimitrov stands between the Spaniard and a place in the final of a tournament he won in 2005. Nadal has won eight of their nine previous meetings.

After saving an early break point, Nadal enjoyed success on the Isner serve in the ninth game of the match, thanks largely to a couple of dazzling backhands, and duly served out the first set.

Isner responded impressively, forcing two break points at the start of the second set, only for Nadal to get out of trouble with the aid of a second-serve ace.

A break point for Nadal then went begging, but the top seed proved unstoppable in the subsequent breaker, a classy lob setting the tone as he won seven points in succession to wrap up victory.