Zverev attacked Marozsan's serve and converted three of his seven break-point chances, swatted aside the two break points he faced and won 80% of his first serve points en route to the last four in Miami where he has yet to drop a set.
Despite not dropping a set in windy conditions, Zverev had his hands full with Marozsan, who is making his Miami debut and enjoyed top-10 upsets over Holger Rune and Alex de Minaur on the way to the quarter-finals.
"If he continues playing like that he's going to rise up the rankings very quickly and he's going to be one of those (top 10) guys himself," Zverev said in his on-court interview.
"When we are in control, I think all top players when they are in control they feel like they can manage the match, manipulate the match a little bit in their own favour.
"But against him that's not possible. That's why he has such a great top-10 record and he's an unbelievable player."
Zverev's win, sealed with a break when he unleashed a brilliant backhand down the line, marked his return to the Miami Open semi-finals for the first time since his runner-up finish in 2018.
Zverev will next face either Spanish top seed Carlos Alcaraz or Bulgarian 11th seed Grigor Dimitrov.
