John Isner stuns No. 5 Kei Nishikori to advance to Miami Open semis

John Isner advances to the Miami Open semifinals with a dominant 6-4, 6-3 win over No. 5 Kei Nishikori.

Two days after scoring his first Top 10 win in over a year against No. 6 MilosRaonic, John Isner stormed into the Miami Open semifinals with a dominant 6-4, 6-3 win over No. 5 KeiNishikori. He will play either No. 1 Novak Djokovic or No. 7 David Ferrer in the semifinals. 

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In one of the best performances of his career, Isner completely took the racket out of Nishikori's hand by hitting aggressively and consistently off the baseline. The chipping and slicing off the backhand were minimal from Isner on Thursday, replaced by heavy hitting that kept Nishikori on his heels. Nishikori, a semifinalist in Miami last year, never got a chance to break Isner's vaunted serve. The American never faced a break point in the match and has yet to be broken all tournament. 

Isner fired 13 aces and won a whopping 81% of his second serve points against one of the tour's top returners. Nishikori came into the match having lost no more than two games in the six sets he's played in Miami. But playing in their first career meeting, Nishikori had no answers for the level of offense coming off Isner's racket. With Isner stepping in and taking big cuts on return, Nishikori won just 57% of both his first and second serves. To further emphasize just how good Isner was on Thursday, he won 42% of both first and second serve points on his return. At one point, Isner won eight consecutive points on Nishikori's serve. Struggling to get a read on Isner's serve, Nishikori won 22% of his first serve return points and 18% on second serve returns.

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The last time Isner earned back-to-back wins over Top 10 opposition was at the Cincinnati Masters in 2013, when he beat Djokovic and Juan Martin del Potro to make the final, where he lost to Rafael Nadal. He came into Miami having lost his last 11 matches against Top 10 opponents and had never advanced past the fourth round in Miami, but he's turned his season around after his disastrous 0-2 performance at Davis Cup last month. Regardless of what happens in Friday's semifinal (Isner will play either Djokovic or Ferrer in the night match), Isner will return to the Top 20 on Monday.