Carlos Alcaraz blatantly dismissed a request communicated to him by the chair umpire during his fourth-round outing at the ongoing 2025 Cincinnati Open. The Spaniard's dismissal of the request came after a tense back-and-forth between him and the chair umpire.On Wednesday, August 14, the former No. 1 and five-time Major winner locked horns with Luca Nardi for a place in the quarterfinals of the ATP Masters 1000 event in Cincinnati. Early on in the contest, during a break in play, chair umpire Greg Allensworth asked the Spaniard to cover the logo on his water bottle citing the hardcourt tournament's policies with regards to its sponsors.However, Allensworth's request irked Carlos Alcaraz, with the 22-year-old ultimately refusing to comply. Watch the bizarre interaction between the umpire and the Spaniard below:Coming to the match itself, Alcaraz, the No. 2 seed, secured progress to the quarterfinals of the 2025 Cincinnati Open with a 6-1, 6-4 win over Nardi. The Spaniard is set to square off against ninth seed Andrey Rublev in the last eight.Carlos Alcaraz going into Cincinnati Open QF clash against Andrey Rublev with superior head-to-head recordCarlos Alcaraz (left) and Andrey Rublev (right) at the 2025 Wimbledon Championships (Source: Getty)Carlos Alcaraz and Andrey Rublev have so far faced each other on four occasions. As things stand, the Spaniard has a 3-1 head-to-head lead over the Russian, with their most recent meeting having come at this year's Wimbledon Championships.At SW19, Alcaraz and Rublev faced each other in the fourth round. The Russian won the first set 7-6(5). However, the Spaniard, who was the defending Wimbledon champion at the time, clinched the next three sets 6-3, 6-4, 6-4 to down the Russian.Interestingly, at ATP Masters 1000 level, the pair's sole previous encounter, which came in the quarterfinals of the 2024 Madrid Open, went Rublev's way. On that particular occasion, it was the Russian who stormed back into the contest after losing the first set. After his win over Alcaraz in Madrid, Rublev spoke up about how staying calm throughout the match helped him come out on top."I think the key was I was completely calm the whole match. I did not say one word, even if I was losing. That was the key and I was able to serve even better near the end. In the beginning, I was not serving that well but little by little, after set one, I served better and better and finished really well," the Russian said.Rublev's victory against Carlos Alcaraz in the Spanish capital last year turned out to be a vital one for the Russian as he went on to win the ATP Masters 1000 claycourt tournament.