Entering the match trailing the Spaniard 0-3 in the pair’s Lexus ATP Head2Head series, the Bulgarian produced a high-quality display at the hard-court event to turn the tables. He timed the ball cleanly off both wings while he used his backhand drop shot to great effect to tuck up Alcaraz, who was aiming to advance to his 13th quarter-final in 14 events in 2023.
The 32-year-old Dimitrov struck 29 winners and responded well after relinquishing a 5-3 lead in the first set to reach his first ATP Masters 1000 quarter-final of the year and 17th in his career after two hours and 10 minutes.
"I stayed in the match, that was the first thing, especially after the first set," Dimitrov said. "I was serving very well throughout the first set and he made a few errors. I pushed him to make a lot of errors at certain moments. At 4-5 he played an amazing game and another at 6-5. I was creating a lot of opportunities.
"After the second break in the second set I think I understood his service games and was able to put more balls in and read his serve a bit better. I think in the third set it was a bit of cat-and-mouse. I think we both played a solid set. He made a few errors and I was very solid and served well when I had to."
Dimitrov, who also reached the last eight in Shanghai in 2017, will next play 22nd seed Nicolas Jarry as he seeks his first title since his 2017 Nitto ATP Finals triumph. The World No. 19 has earned 17 wins against Top 5 opponents, with his previous victory against a player ranked in the Top 2 coming in October 2021 against Daniil Medvedev in Indian Wells. Earlier this month, Dimitrov upset then-World No. 4 Holger Rune in Beijing.
In a tight clash, Dimitrov was on the front-foot throughout against Alcaraz. He followed his low slice into the net, winning 73 per cent (16/22) of points when moving forward, while he was rock-solid on serve in the decider. The Bulgarian won 89 per cent (16/18) of his first-serve points in the third set and sealed the fourth Top 2 win of his career with a smash.
"I knew what I had to do," Dimitrov said when reflecting on his win. "I knew I had to apply constant pressure against him. Even if I was down, even if my shots were not good enough, I had to put him in uncomfortable positions. He doesn't like being on the back foot. I was coming in quite a little bit and trying to put him in awkward positions."
Alcaraz now holds a 63-9 record on the season, with his defeat to Dimitrov damaging his ATP Year-End No. 1 presented by Pepperstone chances. The 20-year-old Spaniard leaves Shanghai trailing Novak Djokovic by 500 points in the Pepperstone ATP Live Race To Turin.
The World No. 2 was chasing his seventh crown of the season and third at ATP Masters 1000 level. Alcaraz has clinched trophies in Indian Wells and Madrid in 2023.