Lorenzo Musetti stuns top seed Alexander Zverev in Vienna to set up Jack Draper semi-final
17th-ranked Musetti came through 2-6, 7-6(5), 6-4 after two hours and 36 minutes to see off the 2021 champion.
"It didn't start how we planned, I was struggling to find the right balance with my forehand and the variation of my backhand," said the Italian who was an Olympic bronze medallist in the summer, just weeks after reaching the Wimbledon semi-finals.
"It's a pretty big win because Sascha really loves to play here, on this court, in these conditions. But, after the first round, I was feeling in good shape and today I showed that."
Musetti will next face world number 18 Jack Draper after the Briton defeated Tomas Machac of the Czech Republic in his quarter-final 6-3, 3-6, 6-1.
"I thought the first set was really physical. It's always tough playing Tomas, he's so solid off the ground," said Draper after booking his place in an eighth tour semi-final.