Kei Nishikori extended to three sets in victory over James Duckworth at Washington Open

Second seed Kei Nishikori was forced to battle back from a set down to defeat James Duckworth in the second round of the Washington Open.

The 25-year-old, who returned to action after withdrawing from the second round at Wimbledon with a calf injury, dropped a tense tie-breaker before regaining control to complete a 6-7 (8-10) 6-1 6-4 win.

In a closely contested opener, both players exchanged breaks but it was Duckworth who forged a one-set lead after Nishikori sent a backhand volley beyond the baseline.

The world No 5 responded well to this setback, taking his fifth break point chance against Duckworth to open a 2-0 advantage, and raced through the second set.

Duckworth desperately tried to stand firm in the decider, but Nishikori broke the Australian in the third game and served out to set up a clash with the winner of Leonardo Mayer’s clash with Blaz Rola.

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Third seed Marin Cilic, the man who beat Nishikori in last year’s US Open final, is also through to the next stage after a 7-6 6-3 win over Hyeon Chung.

Earlier rain delays meant the players did not arrive on court until nearly 1am, but Cilic was not prepared to waste any more time and wrapped up victory to earn a third round meeting with Sam Querrey.

The American had earlier fired down 26 aces on the way to his 6-3 5-7 6-4 win over Japan's Go Soeda.

Watch the Washington 500 and every tournament in the US Series leading up to the US Open live on Sky Sports this summer.