World number three Alcaraz beat his fifth-ranked opponent 6-7 (1/7), 6-3, 6-4, 6-4 and will face either seven-time champion Novak Djokovic or Lorenzo Musetti for the title on Sunday.

Twice Medvedev led with breaks in the first set only to be pinned back by Alcaraz.

Such was his frustration that he was handed a warning for unsportsmanlike conduct by umpire Eva Asderaki for an apparent foul-mouthed reaction to a ball called for bouncing twice as he was broken in the ninth game.

The tournament referee was even summoned to Centre Court by Asderaki, but Medvedev shrugged off the incident to sweep through the tie-break and take the opening set in which he committed only eight unforced errors to the Spaniard's 15.

It was the third time at this year's Wimbledon that Alcaraz had dropped the first set.

Alcaraz recovered impressively, breaking Medvedev for a 3-1 lead in the second having come out on top in the previous game on the back of a 27-shot rally.

The 21-year-old then hit 14 winners in the third set, pocketing the only break in the third game.

Medvedev, who had knocked out world number one Jannik Sinner in the quarter-finals, retrieved a break early in the fourth set.

But Alcaraz kept up his assault, edging ahead again for 4-3 on his way to victory.