LONDON — Andy Murray had all of Britain on edge for five sets.
Juan Martin del Potro only took five points to get the fans buzzing at Wimbledon.
Two victories in two very different matches Wednesday sent Murray and del Potro on to the semifinals at the All England Club.
Murray completed his seventh career comeback from two sets down to top Fernando Verdasco, 4-6, 3-6, 6-1, 6-4, 7-5.
‘‘Made some bad mistakes, poor choices on the court,’’ Murray said. ‘‘And then, I turned it around really well after that.’’
Earlier on Centre Court, del Potro hyperextended his left knee and crumpled to the ground on the fifth point, but shook off the injury for a 6-2, 6-4, 7-6 (5) victory over No. 4 David Ferrer.
‘‘To be honest, I didn’t want to retire [being] in the quarters for first time at Wimbledon,’’ del Potro said. ‘‘And that’s the reason for continuing play. The doctors gave me good anti-inflammatories.’’
Del Potro’s next match is Friday against No. 1 Novak Djokovic, who took down No. 7 Tomas Berdych, 7-6 (5), 6-4, 6-3, on Court 1.
Murray will play No. 24 Jerzy Janowicz, a 7-5, 6-4, 6-4 winner over Lukasz Kubot in the first Grand Slam meeting between two Polish men.
Going against the 54th-ranked Verdasco, Murray certainly made things interesting for the British fans, looking for one of their own to call a Wimbledon champion for the first time in 77 years. He dropped the first two sets, unable to handle Verdasco’s pinpoint serves that reached as high as 136 miles per hour.
Slowly, though, he crept back into the match. In the sixth game of the fourth set, Murray saved a pair of break points — first with a service winner, then with one of his 13 aces. Three games later, he broke Verdasco, then served out the set. In the fifth set, the players held serve for 10 straight games. In the 11th, Murray broke, then served out the match at love.
‘‘I played at a very high level,’’ said Verdasco, appearing in a Grand Slam quarterfinal for the first time since the 2010 US Open. ‘‘And to not be able to win is painful, of course.’’
It was Murray’s second comeback from two sets down at Wimbledon, adding to a 2008 victory over Richard Gasquet.
‘‘Yeah, you’re obviously concerned,’’ Murray said. ‘‘You’re more concerned about losing the match, not thinking so much that, I'm going to lose at Wimbledon. You’re concerned how the match is going and that you may lose. But when you've been in that position a lot of times, you know how to think through it and not get too far ahead of yourself.’’
In the earlier match, it looked as if del Potro would be done before he even broke a sweat.
His left knee mummified in athletic tape, the 6-foot-6-inch Argentine chased an overhead into the corner, but his left foot slipped out from under him. His already aching knee straightened suddenly, then bent backward. Del Potro crumpled to the ground and rolled twice — into the far edge of the court.
‘‘I don’t try for a spectacular fall, but that was really painful for me,’’ del Potro said.
After a break of about 10 minutes, del Potro was back on the court. He broke Ferrer twice in the first set, then moved easily through the second and third against one of the grittiest players in tennis.
‘‘I have my knee problem, but always the opponent, the other players, can have different injuries, too,’’ del Potro said. ‘‘You have to be strong, more than the rest.’’
Across the way, on Court 1, Janowicz beat Kubot to become the first Polish man to reach a Grand Slam semifinal.
After the match, the players hugged at the net for more than 15 seconds, then exchanged shirts the way soccer players often do at their games. A bit later, Janowicz sat in his chair, clasped his hands over his nose and cried.
‘‘Right now, I'm the most happy person in the world,’’ Janowicz said.
About playing Murray, who won his first Grand Slam tournament last year at the US Open, Janowicz said: ‘‘I hope Andy will feel some kind of pressure. I'm sure he'll feel some kind of pressure because Great Britain is waiting for the English champion in Wimbledon.’’
During a tournament with more than its share of twists and turns — to say nothing of slips and slides — Djokovic and del Potro have gone through virtually unscathed, on the scoreboard at least. Neither man has dropped a set.
Djokovic overcame a two-break, 3-0 deficit in the second set to cruise to his latest victory over Berdych, the 2010 Wimbledon runner-up. Djokovic is in his 13th straight Grand Slam semifinal and in search of his seventh major title.
‘‘Coming into the semifinals, I feel physically fresh,’’ Djokovic said.
No. 8 del Potro wouldn’t quite use those terms to describe himself.
He is, however, starting to show the form he used to win his only major championship, the US Open in 2009, which also marks the last time he reached a Grand Slam semifinal. He is 3-8 lifetime against Djokovic, though one of those victories came here, at the All England Club, when he beat the Serb in the Olympic bronze-medal match last year. Del Potro also won their last meeting, earlier this year on hard court at Indian Wells.