Alcaraz has faced Zverev seven times before, with the German baseliner prevailing on four occasions, but it was the young Spaniard who dominated their only previous encounter at a major, with a straight sets win at last year's US Open.
Zverev has put that defeat in quarter-finals in New York down to fatigue after playing a marathon encounter against Jannik Sinner (22) the previous round, and the German got his revenge when he beat Alcaraz in the year-ending ATP Finals in Turin.
"I'm not like (at) the US Open where I was completely dead and where I feel like I'm physically exhausted," Zverev said after beating Cameron Norrie (28) in his last match in Melbourne.
"I'm tired, for sure... but I'm not dead... I expect it to be very different."
Alcaraz, who has been pushed past three sets only once in Melbourne, has spent about five hours less on court than Zverev, and the Spaniard's inventive all-court game has been a highlight of the tournament.
"I'm proud with the level that I am playing," Alcaraz said after his straight sets demolition of Miomir Kecmanovic in the last 16.
"I'm feeling better and better every match that I'm playing and I'm coming into the quarter-final with a lot of confidence."
Men's third seed Daniil Medvedev (27) is aiming to reach his third Australian Open semi-final in four years when he takes on big-serving Pole Hubert Hurkacz (26), who is making his first appearance in the last eight in Melbourne.
Hurkacz, who reached the Wimbledon semi-finals in 2021, has beaten Medvedev in their last two meetings and the Russian knows exactly what he can expect from the ninth seed.
"He serves well. It's tough to return his serve," Medvedev said. "That's going to be the key. I need to stay strong on my serve, don't give him the break, either try to break him or go to the tiebreak and try to win the tie-break."
Top seed Iga Swiatek's (22) shock exit at the hands of Czech teenager Linda Noskova (19) has left the top half of the women's draw wide open, with the 19-year-old now hoping to extend her dream debut in Melbourne to a first-ever Grand Slam semi-final appearance.
Noskova faces off against Ukrainian qualifier Dayana Yastremska (23) in their first-ever meeting.
China's Qinwen Zheng (21), the last seed standing in that half of the draw at number 12, meets Russia's Anna Kalinskaya (25) in the first match of the evening session on Rod Laver Arena, with a first ever trip to a major semi-final the reward on offer for both players.
