'Disgraceful': Nick Kyrgios' opponent injures dad in crazy 'meltdown'

Things might be a little tense in the Tsitsipas household right now.

World No.6 Stefanos Tsitsipas went down to Nick Kyrgios in a three-set thriller at the ATP Cup on Tuesday night, but it was a crazy incident in which he injured his own dad that the Greek star will have a hard time living down.

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Tsitsipas was fuming after dropping a gripping first set tiebreaker against Kyrgios, lashing out in frustration with his racquet.

The problem was, his father and Greece captain Apostolos Tsitsipas was sitting right next to him when he hit out in disgust, catching his dad on the arm with the swinging racquet.

Tsitsipas Sr. jumped to his feet, gesturing angrily at his son who didn't even appear to acknowledge what he'd done.

The 21-year-old's mother could then be seen leaning over the railing apparently scolding her son over the ugly incident.

The crazy scenes left fans in disbelief, with many criticising the Greek star’s behaviour.

It appeared to have little effect with Tsitsipas then receiving a point penalty for unsportsmanlike conduct early in the second set when he smashed a ball into his unfortunate bench, this time just missing his dad.

‘It happened accidentally’

That was enough for his father, who relocated behind the court-side bench for the rest of the match as Tsitsipas' mum returned to give her son another spray.

"It happened accidentally. I didn't mean to do it and straight away forgot about it and moved on from there," Tsitsipas said.

"I wasn't aiming to do that, so it went out of control, unfortunately."

Kyrgios overcome his hot tempered opponent to clinch victory for Australia in in Brisbane after teammate John Millman's nail biting win earlier in the evening.

World No.30 Kyrgios returned from injury to claim a 7-6 (9-7) 6-7 (3-7) 7-6 (7-5) win in more than two-and-a-half hours at Pat Rafter Arena.

All eyes were on Kyrgios to see if he would be on his best behaviour after starting the year with a suspended 16-match ban hanging over his head.

But the former world No.13 looked like a choirboy compared to the hot tempered Tsitsipas on Tuesday night.

Not that Kyrgios was judging his Greek opponent.

"I didn't see it (incident). I don't think he meant it as well. I don't think you should be giving it too much attention or looking too far into it, to be honest," Kyrgios said.

"I've done some stupid things as well in the heat of the moment, so it was obviously an accident."

Kyrgios held his nerve to give Australia an unbeatable 2-0 lead, ensuring the hosts went through the ATP Cup round robin stages undefeated with three straight victories to top Group F.

They are set to play Great Britain in a quarter-final in Sydney on Thursday.

Australia completed a 3-0 whitewash of Greece when John Peers and Chris Guccione sealed a straight sets win over Markos Kalovelonis and Petros Tsitsipas.

Kyrgios missed the last tie against Canada with a back complaint but stepped up as Australia's No.1 player on Tuesday after world No.18 Alex de Minaur was rested against Greece.

Australian captain Lleyton Hewitt said he had rested de Minaur for precautionary reasons and ruled out injury on Tuesday night.

Earlier, Millman drew first blood for Australia when he outlasted a gutsy Michail Pervolarakis 4-6 6-1 7-6 (7-1).

World No.48 Millman had to dig deep against an opponent ranked 438 places lower than him who was also battling an ankle complaint from the second set.

With AAP