Stefanos Tsitsipas said he did not mean to hit his father and coach Apostolos with a racket swipe in a mid-match fit of rage during Tuesday's ATP Cup loss to Australia's Nick Kyrgios.
The Greek 21-year-old, ranked sixth in the world, lost 7-6(7) 6-7(3) 7-6(5) and took out his frustration after losing the opening set tiebreak with two racket swipes near the team bench, the second of which bruised his father's arm.
Apostolos immediately got up from his chair in shock and went up to the stands to sit with the rest of the Greek team while Tsitsipas, who was docked a point and warned by the umpire, received an earful from his mother Julia Apostoli.
"It happened accidentally, I didn't mean to do it and straight away forgot about it and moved on from there," Tsitsipas told reporters.
"It happens, I wasn't aiming to do that. It just went out of control, unfortunately.
"Maybe I'll stay in my room for three days, grounded by my father," he added, laughing.
Kyrgios, no stranger to on-court outbursts, did not see the incident himself but said that it should not be getting too much attention.
"I've done some stupid things as well in the heat of the moment, so it was obviously an accident," he said after Australia's 3-0 victory saw them top the group.
Despite his meltdown and loss to Kyrgios, Tsitsipas, who made the Australian Open semi-finals last year said he was happy with how he was doing heading into the opening Grand Slam of the year at Melbourne Park this month.
He has so far totted up just one win out of three, also losing to Canada's Denis Shapovalov in two tough tie-break sets while thrashing world number seven Alexander Zverev.
"There's nothing I'm worrying (about) right now. I feel good with my game, with my physical (condition)," he said.
"The only thing that might concern me a little bit is when I come close to matches I feel like I've lost this competitiveness within me.
"I remember a few months ago I had the tendency to be more in the zone, really, really concentrated and knew what I was doing, playing very aggressive," he added.
"Sometimes I feel like I get too passive and I'm not really into the match, which, I don't know, probably a few technical issues that I have to work on and not to think too much of my technique and work on my tactics more."