The British No 1, from Beverly, looked to be on his way to the third round at Wimbledon for the second straight year when he led his veteran Spanish opponent by two sets and 3-0 but he let Verdasco back in and then appeared to hurt himself in a slip on the baseline.
Edmund has had a difficult season, with a left knee problem dogging him since last October, but he received treatment to his right knee here as well as his back at consecutive changes of ends, speaking to both the doctor and the trainer.
Edmund’s movement was certainly compromised and his resistance ran out as Verdasco wrapped up a 4-6 4-6 7-6 (3) 6-3 6-4 victory to book a third-round date with Italian Thomas Fabbiano.
But Edmund played down the impact of the slip in the eighth game of the third set, saying: “I think my leg just straightened. In that moment, I felt something. I was able to play on from that.
“It didn’t hold me back at all. I physically was not able to keep going with the power and reaction and stuff. I need to improve physically for next time I step on court. Being able to play three and a half, four hours, you need to put the work in. It doesn’t just happen.
“At the same time, I’m still up in the match, and the 3-1 game cost me. That was my fault.”
The turning point came in the fifth game of the third set, with Verdasco looking like he knew his time was up.
Edmund led 40-0 only to lose the game with five unforced errors, giving Verdasco a reason to believe again and changing the momentum of the match.
It is the second time Edmund has lost from a winning position against 35-year-old Verdasco in two months having also slumped to defeat from a set and 4-1 up on clay in Rome.
When told that John McEnroe had accused Edmund of blowing it, the 24-year-old said: “That’s his opinion. I’m obviously disappointed. There will be for sure a lot of people saying that.”
Edmund has only won eight tour-level matches this season compared to 24 at the same stage 12 months ago, but he denied the issue is mental as well as physical.
“I’m a good tennis player,” he said. “You don’t lose that match from not having enough tennis matches, in my opinion.”
The good news for Edmund was that his left knee held up OK and he remains hopeful of finishing the season strongly. He will concentrate on training before returning to action at the Citi Open in Washington at the end of July.
“The tennis season is so long,” he said. “This time last year, I got ill straight after Wimbledon, won two matches in the US hard court series, I think (he actually won three). I literally have nothing to defend there. There’s a great opportunity there.
“It would be nice to go in there feeling really good, having a good run of matches. For sure there is stuff to play for.”
There was defeat too for Hull’s Paul Jubb, the 18-year-old suffering a first-round loss in the men’s doubles.
After losing in in four sets on Tuesday to world No 69 Joao Sousa, Jubb and Jack Draper bowed out of the doubles losing to Colombian second seeds Juan Sebastian-Cabal and Robert Farah 6-1 6-4 6-2.
Novak Djokovic sailed smoothly into the third round after a trouble-free straight-sets win over Denis Kudla.
The reigning champion’s defence of his title was never threatened by the American and he strolled to a 6-3 6-2 6-2 win on Centre Court.
Karen Khachanov got through a tricky test against Queen’s champion Feliciano Lopez.
The 10th seed came from a set down to win 4-6 6-4 7-5 6-4.
Stan Wawrinka crashed out in the second round, losing in five sets to unseeded Reilly Opelka 7-5 3-6 4-6 6-4 8-6.
Daniil Medvedev, the Russian 11th seed, is through after he beat Australian Alexei Popyrin 6-7 (8-6) 6-1 6-4 6-4.
Cori Gauff, the 15-year-old sensation who defeated Venus Williams in round one, continued her stunning progress by beating former semi-finalist Magdalena Rybarikova.
Playing under the lights of the Court One roof, the American put in another nerveless display to win 6-3 6-3.
Gauff will play world No 60 Polona Hercog of Slovenia in round three after she beat 17th seed Madison Keys.
Former world No 1 Caroline Wozniacki, who has never made it past the fourth round, beat unseeded Russian Veronika Kudermetova 7-6 (7-5) 6-3.
Seventh seed Simona Halep was taken the distance in the all-Romanian showdown on Court Two.
The 2018 French Open champion eventually beat Mihaela Buzarnescu 6-3 4-6 6-2 in an hour and 51 minutes.