Daniil Medvedev once again courted controversy, this time with an outburst at chair umpire Mohamed Lahyani at the 2025 Shanghai Masters. The Russian referenced the retired Rafael Nadal in his verbal tirade after being given a code violation during his third-round clash with Learner Tien on Wednesday.Medvedev had lost his two previous meetings with Tien, meaning he had a mental mountain to climb in Shanghai. He started off well enough, taking the opening set in a tiebreak and then breaking for a 3-0 lead in the second. However, ghosts of his previous losses returned, as the former World No. 1 ended up losing the break advantage, allowing Tien to force another tiebreak.This time, the American capitalized, securing a mini break. It was here that Medvedev exploded, directing his fury at Lahyani, who thought he was taking too long on the return when Tien was ready to serve.After the violation was handed, Medvedev snapped back at Lahyani, recalling all the times he faced Nadal. The Russian was of the opinion that Nadal had always made him wait, but never received a code violation."All my life, I've been serving & waiting for Rafa for 55 seconds," Medvedev said. "And you give me a code violation on the first occasion. I played Rafa 5 times, there was not one time I was ready to serve and he was ready to return. He didn't get one time violation. To me, today, at the slightest thing you give it to me. I always waited to return, and you didn't give it to him. You're crazy. Completely crazy."Medvedev went on to lose the set, but bounced back to take the third set 6-4 to reach the quarterfinals of the Masters 1000 event.Daniil Medvedev to take on Alex de Minaur next at Shanghai Masters2025 Shanghai Rolex Masters - Day 10 - Source: GettyFollowing his win over Learner Tien, Daniil Medvedev will take on Alex de Minaur in the quarterfinals of the Masters 1000 event. The Aussie beat Nuno Borges in the Round of 16 and is yet to lose a set.A win against De Minaur would pit Medvedev against either Felix Auger-Aliassime or Arthur Rinderknech in the semifinals, with a potential final against Novak Djokovic looming.