When Daniil Medvedev decided to take on the hostile New York crowds as well as his opponents at the US Open it seemed a doomed and dangerous path to a first grand slam title.
But the lanky Russian is now into his first Grand Slam semi-final after a 7-6(6) 6-3 3-6 6-1 win over Stan Wawrinka on Tuesday and it comes as no surprise to his coach Gilles Cervara, who described his pupil as a 'genius'.
"It`s like to coach a genius," Cervara told reporters. "Sometimes a genius, you don`t understand them. It`s like this. They are different."
Whether Medvedev`s decision to turn the Flushing Meadows crowds against him was a gaffe made in the heat of the moment or a stroke of inspirational genius is up for debate but the results are not.
The 23-year-old Russian embraced his villain role, harnessing the negative energy and using it to fuel a run to the semi-finals.
In his third-round win over Feliciano Lopez, the 23-year-old Russian angrily snatched a towel from a ball person, threw his racket and showed the crowd his middle finger, which led to fines totalling $9,000 and a shower of boos.
The match ended with Medvedev, arms raised amid a chorus of jeers, sarcastically thanking the spectators at Louis Armstrong Stadium then telling the New York crowd to bring it on.
The crowd let him have it again after his fourth-round win over Dominik Koepfer on Sunday when he performed a dance after match point.
Perhaps sensing he had squeezed as much as he could out of the bad boy ploy Medvedev stepped back on Tuesday, offering an apology for his behaviour, saying, "I try to be myself guys".
"It`s easy with Daniil," said Cervara. "He`s smart enough to understand that if he did the wrong thing or not, if he continues to go in this way it will put more trouble for him."
"Of course he likes to play also with it, but he didn`t cross too much the line, I would say."
Medvedev has displayed plenty of mental toughness with his willingness to absorb abuse from the fans but it was his physical fitness that was the big question mark following his quarter-final win.
Early in the first set against Wawrinka the Russian was forced to take an injury time out to deal with a problem with his left quadricep. Although he continued Medvedev said later that he had considered quitting.
Cervara also acknowledged the issue but dismissed it as "no big deal" and with two days to prepare for his semi-final would be ready to face the winner of 20-time Grand Slam champion Roger Federer and Grigor Dimitrov.
"Tough. Yes, I will tell you why," said Cervara. "You see today it was a tough match because he had some problem on his leg."
"But still, with this, he found a way to fight and to play good tennis with this, to put Stan maybe in trouble with no game."
"His mental game is getting stronger and stronger. That`s one of the parts of his success in his career and today."