The German third seed defeated the 19-year-old Spanish sensation Alcaraz 6-4, 6-4, 4-6, 7-6 (9/7) in three hours and 18 minutes.
Zverev went on to win his first Grand Slam over a top-10 player in his second consecutive last-four match at Roland Garros.
“I hope I can beat him before he starts beating us all and we have no chance,” Zverev said. “The match was swinging his way. I’m very happy to have won the tie-break.”
Alcaraz has won four titles this year, including two Masters 1,000 events, but made 56 unforced errors as he missed out on a chance to reach the first major semifinal.
મેચ Tonight’s match has all the classic compositions, but this afternoon the four-set win was beautiful for lexAlexZverev 🔥… https://t.co/SNXrl4mFMl
– Rolandgarros (landrolandgarros) 1654035300000
Instead, Olympic champion Zverev reached the last four in Slam for the fifth time in his career and retained his bid for the first title in one of the sport’s four biggest events.
It also gave him a measure of revenge for the heavy defeat he suffered against Alcaraz in the Madrid Masters final earlier this month.
Alcaraz delighted the crowd of Court Philippe Chatterjee with a rally to win the third set.
In the dramatic fourth set, Zverev missed a tie, but won his second match point in a tie-break.
Alcaraz paid for 16 unforced errors as Zverev thanked the opener for a lone break in five games.
“I knew I had to do my best to beat him.” No.3
– Rolandgarros (landrolandgarros) 1654046100000
He was the third-ranked player in the world to also draw the first blood in the second set, as Alcaraz netted at the second break point in the seventh game, before giving Zverev a 5-3 advantage to hold on confidently to love.
Alcaraz managed to lift himself to attack Zverev’s next service game, but saved a break for Germany and managed to get him out with an ace for a two-set buffer on his third set point.
The crowd tried to lift Alcaraz as he started trying to come back from two sets down and win for the first time in his youth career.
He improved a bit and held on to his first four service games without difficulty before digging deep to save a break point in the ninth game of the third set.
That brush with the exit door excited the youngster, and he quickly brought in two set points with a brilliant passing shot.
It all left there @ @ AlexZverev x @ alcarazcarlos03 # RolandGarros https://t.co/rNOd1RqfxL
– Rolandgarros (landrolandgarros) 1654021950000
He only needed one to push for the fourth set, which broke Zverev for the first time as the 25-year-old widened.
Alcaraz looked set to have the most success in the next set, but with the help of a wonderful backhand, Zverev advanced to the ninth game when his opponent made a double fault at the second break point.
But Zverev failed to serve the match, as Alcaraz got a grand return in the corner and then whipped the backhand to break the straight back.
The highest quality tie-break took place, with both players hitting a series of breath-taking winners.
The stunning backhand up the line gave Alcaraz the first set point, but he was trapped in the net.
Zverev hit the net on his first match point but quickly brought in a second, which he took with a hefty return from the backhand.