For Greg Allensworth, dealing with hecklers is almost becoming part of the job description. After several crowd confrontations, including the Reilly Opelka incident last year, things haven’t always ended smoothly. But this time, Allensworth wasn’t taking any chances, stepping in firmly to defend Jakub Mensik and deliver a stern message to the disruptive fan.

During his second-round match at the National Bank Open, Jakub Mensik reported the heckler to chair umpire Greg Allensworth, who responded firmly, warning the fan not to disrupt the players. “Sir at the back of the court, the players have excellent coaches to get them through the match, so please stop. Thank you,” Allensworth made his message crystal clear on the mic, telling the fan to shut up. The blunt response immediately drew reactions from both Mensik and the crowd.

As the stands erupted in laughter, Mensik could only smile at the crowd before getting back to business. The incident occurred at a crucial point as Mensik was serving for the match at 5-4, and the game was tied at 15-15.

The disturbance could well have given his opponent Terence Atmane an opening at that point. But Mensik kept his cool and wrapped up the match on his serve, while Allensworth’s warning seemed to do the trick on the disruptive fan. However, while Allensworth has become one of tennis’ most talked-about chair umpires, it hasn’t exactly been for the right reasons.

Reilly Opelka knows this story all too well. At the Dallas Open last year, Allensworth handed the American a code violation and point penalty after Opelka responded to a disruptive fan with an expletive. The incident left Opelka branding Allensworth the “worst chair umpire in the ATP.” And then came Daniil Medvedev.

At the 2025 US Open, during his first-round clash with Benjamin Bonzi, a photographer walked onto the court while Bonzi was serving for the match. Allensworth awarded Bonzi another first serve after the disruption, a decision that sent Medvedev into a meltdown. The Russian repeatedly turned to the crowd and shouted, “What did Reilly Opelka say?”

Luckily for Mensik, Allensworth had his back in Montreal. But heckling is hardly new territory for the young Czech star. While he raised the issue with the umpire at the National Bank Open, Mensik has previously handled rowdy crowds at the French Open with remarkable composure, all thanks to a little trick he picked up from Novak Djokovic.

Jakub Mensik uses the Djokovic trick to handle hecklers

Mensik has dealt with disruptive fans before, but he has already passed one of the toughest tests in tennis: handling the famously passionate French crowd while taking on a home player at Roland Garros. The Czech pro felt the pressure of the crowd when he faced home favorite Alexandre Muller at Roland Garros last year and managed to win in four sets.

The Czech drew inspiration from Novak Djokovic in terms of dealing with a crowd, as he mentally conditioned himself on the court to think the crowd was cheering for him, while they were actually voicing their support for the home player.

“Like Novak says, when sometimes the crowd is against him … I was repeating in my head when they were cheering or shouting his name, I was trying to focus that they are shouting my name,” said Mensik to the press after the match.

Djokovic is not only an idol for Mensik, but the Czech had his biggest career moment at the expense of the Serb when he beat Nole in the 2025 Miami Open final, winning a Masters 1000 title. He could not generate any notable results last year, but 2026 has seen a resurgence in Mensik’s form.

Mensik has a 27-13 win-loss record this season, having won a title in Auckland and having a breakthrough run at the French Open, where he reached the semifinal. Having won against Atmane in Montreal, the Czech will now face Botic Van de Zandschulp in the next round, with the Dutchman already having beaten the likes of Daniil Medvedev and Hubert Hurkacz in earlier rounds.