He's known as Marinko ''Mad Dog'' Matosevic, and the Australian tennis player lived up to his nickname during his opening round match at an ATP tournament in the US overnight.
The 29-year-old Melburnian is likely to face a fine after a meltdown at the end of his encounter with Nicolas Mahut at the Cincinnati Masters.
Matosevic refused to shake the umpire's hand, kicked out towards an on-court camera and appeared to spit and curse.
Remarkably, the dummy spit came after Matosevic won the match, downing the Frenchman in straight sets 6-4, 7-6.
It was in the dying stages of the encounter that Matosevic believed he had served a match-winning ace. But the umpire ruled that his serve was out.
Matosevic, the world No. 89, went on to triumph, but his fury was clear for all to see.
He congratulated Mahut, but then walked off without shaking the umpire's hand.
His outburst earned him few fans on social media, with one person suggesting he needed ''a lesson from the [Roger] Federer school of class''.
It's not the first time Matosevic has had a post-match meltdown.
Following his first-round loss at the Australian Open this year, he took aim at his coach Mark Woodforde in the press conference for the lack of verbal support during the match.
He had also complained to the chair umpire about the use of the ''Mad Dog'' nickname from the crowd.
In the fifth set, the chair umpire finally asked fans to ''please use players' names if you want to support them''.
In June, after Andy Murray hired former women's world No 1 Amelie Mauresmo as his coach, Matosevic said he would definitely not be following in his footsteps.
''For me, I couldn't do it since I don't think that highly of the women's game,'' Matosevic said.
''But, you know, his mum coached him and she did a great job with him so we'll see what happens.''
Matosevic last week withdraw from the Toronto Masters, won on Sunday by Jo-Wilfried Tsonga, due to a shoulder complaint before his first match.
- Fairfax Media