At 25 years and 30 days, the Spaniard is the second youngest man in the Open Era (since 1968) to reach 16 Grand Slam championship semi-finals. Only Sweden's Bjorn Borg (by two days) achieved the feat at a younger age.
Top seed Nadal will next challenge No. 4 seed Andy Murray in the semi-finals for a second successive year. Last year, Nadal beat Murray 6-4, 7-6(6), 6-4 at the All England Club. He has an 11-4 overall record against the Scot, who won the recent AEGON Championships for the second time.
Fish, who had dropped serve only once in 65 service games, got off to a nervous start when he was broken to 30 in the first game and to 15 in the seventh game. Fish's lack of confidence on serve was in stark contrast to Nadal, who fired down deliveries at up to 125 miles per hour, but the American did break Nadal to trail 3-5. Having won just 24 per cent of second service points in the set, Fish soon found himself in trouble again. Nadal forced Fish into successive errors and clinched the 36-minute opener.
Nadal went from strength to strength after saving two break points in the third game of the second set. Showing no signs of the foot injury that hindered him in his fourth-round win over Juan Martin del Potro, Nadal won 12 straight points on serve to lead 5-2 and he hit 13 winners overall to take a two-sets-to-love lead.
Both players weathered storms early in the third set, yet it was Fish who grew in confidence. Hitting serves of up to 131 miles per hour, Fish stayed in touch and just as the set looked like it was going to be decided on a tie-break, Nadal looked fragile. At 5-6, the Spaniard fell to 15/40. Fish hooked a forehand into the tramlines on his first set point opportunity but he made sure on the second point with a clean forehand winner down the line.
Clever court craft helped Nadal break for 2-1 early in the fourth set, just as Fish was gathering momentum. The World No. 1 maintained the advantage through to the end of the Centre Court match, which lasted two hours and 53 minutes, for his 50th win of the season (50-7 overall).
Nadal is bidding to win his 11th major title and become the second player after Borg to complete the Roland Garros-Wimbledon double on three occasions. He hit 43 winners and committed just 13 unforced errors, with 21 of 27 successful forays to the net. Fish, who remained aggressive, hit 12 aces and made 27 unforced errors.
Fish was appearing in his third major championship quarter-final. He also lost in the last eight at the 2007 Australian Open (l. to Roddick) and the 2008 US Open (l. to Nadal). He has taken part in 34 Grand Slam championships during his career.