Cristian Garin did not drop serve toppling top-seeded Alexander Zverev 6-4, 6-4 to set up a Munich semifinal vs. No. 3-seeded Taylor Fritz.
Tsitsipas and Ruud are two steps from another final in Barcelona.
The world No.1 kicked off her clay-court season with an impressive victory.
Defending champion Holger Rune swept Daniel Elahi Galan 6-4, 6-2 to score his 10th consecutive victory on Munich's red clay.
World No. 53 Arantxa Rus upset top-seeded Anastasia Pavlyuchenkova 6-3, 1-6, 6-3 to advance to the Rouen quarterfinals.
Could a peak Bjorn Borg challenge King of Clay Rafael Nadal in a French Open final? A tennis historian offers the answer.
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