Novak Djokovic thrashed Taylor Fritz while Carlos Alcaraz fought back from a set down as the top-ranked pair reached the semi-finals of the Cincinnati Open.

World number one Alcaraz won 4-6 6-3 6-4 against Max Purcell to set up a semi-final tie with Poland's Hubert Hurkacz.

The pair are on course to meet for a rematch of last month's Wimbledon final, which Alcaraz won.

Second seed Djokovic is playing in his first tournament on American soil since 2021 after missing last year's US Open and other tournaments because of his Covid vaccination status.

He will bid for a 24th Grand Slam title at the US Open, which gets under way on 28 August.

The Serb dominated the first set against home favourite and ninth seed Fritz and, despite finding himself 4-2 down in the second, rallied to win four games in a row and wrap up the victory.

"I just managed to get off the blocks really strong, played an almost perfect, flawless first set," Djokovic said.

"Then I started off really poorly in the second and handed him the break, but from 2-4 down, I played really four solid games in the second. Just overall a great performance."

Meanwhile, Alcaraz was taken to a third set for a third straight match by Australian qualifier Purcell.

"It was really tough," said Alcaraz, who will defend his US Open title later this month.

"I returned well on court and that was the key to getting the win today, to return very well and to focus."

Elsewhere, Alcaraz's semi-final opponent Hurkacz, ranked 20th in the world, beat Australian Alexei Popyrin 6-1 7-6 (8-6).

The Pole was narrowly beaten 3-6 7-6 (7-2) 7-6 (7-3) by Alcaraz in last week's Canadian Open, before the Spaniard exited the tournament with a quarter-final defeat by American Tommy Paul.

Germany's Zverev, who won the Hamburg Open last month, will face Djokovic in Saturday's other semi-final after the 16th seed cruised to a 6-2 6-3 win over Frenchman Adrian Mannarino.