London - Sam Querrey sent hobbling defending champion Andy Murray crashing out of Wimbledon on Wednesday, reaching his first Grand Slam semi-final at the 42nd attempt.
One year after knocking out 2015 champion Novak Djokovic in the third round, 29-year-old Querrey, the world number 28, won 3-6, 6-4, 6-7 (4/7), 6-1, 6-1.
World number one Murray's challenge petered out when he began limping off his right leg, his movement severely compromised by a recent hip problem.
Querrey will face either Gilles Muller of Luxembourg, who stunned Rafael Nadal in the fourth round, or former US Open champion Marin Cilic for a place in the final.
"I'm still in a state of shock. I'm glad I hit that last serve in," said Querrey who finished with 27 aces and 70 winners.
"I didn't start the best but I just kept swinging away and found my groove in the last two sets."
Querrey is the first American man in the semi-finals of a Grand Slam since Andy Roddick finished runner-up at Wimbledon in 2009.
"It feels great. It's a dream come true to be in the semi-final at Wimbledon, it's very special," Querrey added.
There was no sign of the drama to come at the start of Wednesday's match.
Murray, 30, was supreme in the first set, carving out the key break for 2-0 and taking the opener on the back of just two unforced errors.
The Scot was a break to the good at 4-3 in the second before Querrey unexpectedly reeled off three straight games to level the quarter-final, firing 16 winners, twice as many as the top seed.
Murray restored his lead after Querrey played a sloppy tiebreak in the third set.
However, the champion's afternoon on Centre Court began to unravel as his movement became increasingly limited.
Limping badly off his right leg, Murray was being run ragged and was broken three times in a 22-minute fourth set.
The fifth set followed a similar plot line, lasting 27 minutes as Murray won just one point off the American's serve