The towering 27-year-old twice came from a set down to continue his fine run in south-west London with a thrilling 3-6 7-6 (4) 3-6 6-4 6-4 victory in just over three hours.

His impressive win over two-time grand slam finalist Tsitsipas follows success over British number one Cameron Norrie and sets up a last-eight meeting with third seed Daniil Medvedev.

"I feel like I'm living a dream right now," said Eubanks. "This is absolutely insane.

"When you paint all of the context - I've tried so much to block everything out and just focus on the next match - it's surreal, it's unbelievable.

"This has been a dream come true."

Eubanks, ranked 43rd in the world, had only won two grand slam matches prior to arriving at SW19.

He made an unconvincing start to the contest on Court Two but battled back and floored Tsitsipas - conqueror of Andy Murray - with 53 winners, including 13 aces.

Eubanks recently said he hated playing on grass but is currently enjoying a nine-match winning streak on the surface.

"Those words will never come out of my mouth (again) for the rest of my career," he said.

"The grass and I, we've had a very strenuous relationship over the years but right now I think it's my best friend."

Earlier, world number three Medvedev eased into his maiden Wimbledon quarter-final after Jiri Lehecka was forced to retire injured.

The 27-year-old Russian was in control on Court One and had just gone two sets ahead at 6-4 6-2 when his Czech opponent pulled out.

Lehecka received treatment during a medical timeout at the end of the opening set but initially battled on in some discomfort before opting for a premature departure.

"I honestly did not (realise) until he retired," he said of Lehecka's injury.

"I saw that maybe his movement is a little bit restricted but the way he was throwing the ball I thought that it was not causing him enough trouble but then when he retired, I was like, 'OK, I see it different'.

"I feel sorry for Jiri. Hopefully he can recover fast and he has a lot more grand slams to come ahead of him."

Lehecka showed some touches of class but his performance was undermined by a series of errors and, ultimately, his fitness issue.

"This is not the way how I wanted to finish the match," the 21-year-old said.

"Of course all the credit to Daniil, because he played another solid match, but for me still I felt that if I was able to show my maximum level, then it would have been a much more better match than it was today.

"But unfortunately the injury got much, much worse during the match, and I wasn't able to compete on the highest level."

Lehecka struggled to deal with the power of Medvedev, with one of his returns of serve flying off court and landing in a spectator's drink.

Both players were then forced to sit down during the sixth game of the second set due to a medical emergency in the crowd.

The affected spectator eventually walked out of the arena with the aid of medics following a delay of around 10 minutes.

Finished New Zealand Women in England ODI Series