Medvedev, champion in Cincinnati in 2019, honed his game for his upcoming US Open title defense with a 7-6, 6-3 win over 11th seed Fritz, while Tsitsipas couldn’t handle only one break chance in a three-set slugfest with Isner but it was enough to clinch a 7-6, 5-7, 6-3 win.
Medvedev’s victory was fueled by 18 aces while a missed Fritz, one of the match’s heavy hitters, had just three offset by three double faults.
Isner, the biggest server in men’s tennis with almost 200 aces more than his nearest rival Nick Kyrgios, also had 18 aces but it was still not enough to put aside his patient Greek opponent.
While it seemed like a comfortable victory for Medvedev, it was anything but, with the Russian saving three set points in the opener before eventually winning 7-1 in the tie-break.
From then on, Medvedev took charge, grabbing the only break of the game early in the second, and that would be all that was needed to advance to the last four in Cincinnati for the second year in a row.
“The first set he was a bit above me,” admitted Medvedev. “He had a lot more chances than me on my serve, but I managed to stay.
“There were set points where I could have missed it and no one would have talked about it, it would have been normal.
“But I managed to stay in the set and that helped me win the match.”
Breaks were equally rare in the Tsitsipas and Isner game.
After a first set without a single break chance for either player, Tsitsipas took the lead taking the tiebreaker 7-5.
The first break opportunity would eventually present itself in the 11th game of the second set when Isner would need three chances to convert and take a 6-5 lead, then hold serve to send the contest to a decider.
Down to 4-3 and with Isner on serve, Tsitsipas would finally get his one and only break chance, and he made it count – striking the air with delight as he watched the American’s return sail long for a 5-3 lead.
“I think the most important thing with him is to try to stay patient because there will be a lot of situations that you can’t really control,” said Tsitsipas, who next faces Medvedev for a place in Sunday’s final.
“It all came down to very few points in the end… I was just able to hold on and play one more ball without giving him a lot of work.”
Britain’s number one Cameron Norrie held off third seed Carlos Alcaraz to claim a 7-6, 6-7, 6-4 victory and book his place in the semi-finals, where he will face Borna Coric after the Croatian defeated Felix Auger-Aliassime 6-4, 6-4.
Norrie squandered a 4-1 lead in the second set before coming back from 1-3 down in the decider to topple the 19-year-old Spaniard in just over three hours.
“I just wanted to hang on to him. I thought I had the physical advantage and the legs and just tried to make every rally as physical as possible,” Norrie said.
Alcaraz, looking for his third ATP Masters 1000 title this season, had to regret a string of break point opportunities, converting just two of 13 as Norrie got the better of his opponent’s serve at 4-4 in the third set to secure the win.
“It was a really good fight and exactly what I needed before the US Open,” added Norrie.
