Dimitrov, the 2014 winner who came through qualifying this year, was his own worst enemy. He had a better first serve and more break chances but hurt himself with 16 unforced errors and seven double faults.
“Grigor is a top player on any surface, but especially on grass. But I played really well from the beginning to the last ball,” Alcaraz said.
“I’m a guy who learns quite fast and I’m feeling really comfortable playing on grass.”
Alcaraz also improved to 8-0 this year in quarterfinals.
In the semifinals, he’ll face Sebastian Korda, into his first grass semifinal as well. Korda became the first American to reach the Queen’s semis in 11 years after beating Cameron Norrie 6-4, 7-6 (1).
The exit of Norrie, the 2021 runner-up and a Wimbledon semifinalist last year, meant Britain has no player in singles or doubles in the weekend at Queen’s for the first time in 11 years.
Rune topped Lorenzo Musetti 6-4, 7-5 and said he wasn’t fazed when the Italian hit him with an overhead smash.
“He can do what he wants,” Rune said. “I mean, it’s not the best thing to do, for sure. But again, it is legal. He can hit the ball where he wants to.
“It just gave me fire in the belly to beat him even more. I’m super happy to manage to beat him in two sets. It feels good. I’m in the semifinal, he’s not.”
De Minaur won against unseeded Adrian Mannarino 6-4, 4-6, 6-4 in their first meeting on grass, giving him a fourth win in five career matches against the Frenchman.
Carlos Alcaraz reaches first ATP semifinals in grass event