Nadal will attempt to extend his unbeaten 11-0 semi-final record at the Foro Italico when he faces first-time ATP Masters 1000 semi-finalist Reilly Opelka on Saturday.
Opelka saved all four break points he faced to defeat Argentine qualifier Federico Delbonis 7-5, 7-6(2) on Grand Stand Arena.
Nadal, the nine-time champion, saved all eight break points he faced in the second set to win after two hours. The Spaniard's win ended a streak of three straight losses against the World No. 6 and improved his ATP head-to-head record against Zverev to 6-3.
"[I am] happy. I played a very solid match with not many mistakes, playing the way that I have to," Nadal said in his post-match interview. "[It is] an important victory for me against a great player."
Nadal is now just two wins away from equalling Novak Djokovic's record haul of 36 ATP Masters 1000 titles. The 34-year-old is also attempting to win 10 or more titles at a single event for the fourth time. Nadal already owns 13 Roland Garros crowns, 12 Barcelona trophies and 11 Monte-Carlo titles.
"[I will face] a big chance against a player who has almost an unreturnable serve. [Reilly] is playing well," Nadal said. "I need to be very focused with my serve and then try to be ready to accept [the situation] and be [engaged] on the return. That is what I am looking for."
In the first set, Nadal used his forehand to control the centre of the court and found consistent success behind his second-serve return. The 35-time Masters 1000 titlist raced into a 4-0 lead, but Zverev played with increased aggression from the baseline to reduce the gap. When serving for the set at 5-3, Nadal targeted Zverev's backhand to save break point and convert his first set point.
"I think I played more solid than in Madrid. At the same time, conditions are different," Nadal said.
"In Madrid, he (Zverev) was able to create a lot of damage with his serve and then with the first shot. Here, the situation is a little bit different. [These are] a little bit more normal conditions on the clay, so I was able to control a little bit more the game than in Madrid."