The German fired 22 winners and closed out the match in one hour and two minutes on Thursday, the fastest of the tournament so far, and joins defending champion Daniil Medvedev in the semi-finals from the Red Group.

The 24-year-old will face Green Group winner Djokovic on Saturday for the fifth time this year, having lost on three occasions including in the last four of the US Open, but having beaten the Serb in the semi-finals of the Tokyo Olympics.

"I have played Novak in every single big hardcourt tournament this year," the world number three said. "We are making a habit of playing in the later rounds at big tournaments. It is going to be an entertaining one, I think."

Zverev was looking to make a statement in Turin, having won via a retirement in his first match against injured Matteo Berrettini before losing in three sets to Medvedev on Tuesday.

The 2018 champion certainly made his intentions clear in the first set against Hurkacz, breaking the Pole in the first game and racing to a 4-0 lead. It took Zverev only 27 minutes to seal the set 6-2.

However, Hurkacz was not in the mood to leave his first Finals so quickly and recovered his service game to keep the score level in the second.

He might even have had a chance for a break point at 3-2, when Zverev put a first serve out on 40-40. However, the line judge missed it and the 24-year-old Hurkacz did not challenge.

The Pole then hit a number of wayward forehands to hand Zverev a crucial break to lead 5-4, from which the German served out the match to set up a clash with Djokovic in what he'll hope will be a repeat of the 2018 final which he won.

"Today was a tough match mentally because I needed to win, so I was 100% focused," said Zverev.

"It was very up and down, and I am happy to be through and win in straight sets. You can always improve. The margins are always very small between the top players, but to win you have to do the details right.

"I hope I can do that on Saturday."

Australian Associated Press