The 23-year-old battled through physical issues to beat France’s Benjamin Bonzi in the Miami Open first round.

Fearnley, currently ranked 83rd in the world, struggled with a leg injury in the second set before recovering to win 7-6 (8-6) 2-6 6-4.

He will climb above Cameron Norrie to become Britain’s second leading men’s player – behind Indian Wells champion Jack Draper – when the ATP rankings are updated after Miami.

Norrie, 29, lost 6-4 6-2 to Chinese world number 69 Bu Yunchaokete in his first-round match on Thursday.

Former world number eight Norrie is ranked 81st after struggling for form over the past year and is set to fall even further.

This time last year, Fearnley was ranked outside of the world’s top 500 and still studying at Texas Christian University in the United States.

After a meteoric rise since turning professional in June, he is set to reach a new career high after moving into the Miami second round.

Fearnley could break into the top 70 if he goes further at the Masters tournament – the tier of ATP events below the four Grand Slams – although German top seed Alexander Zverev awaits on Friday.

It is a rematch of their Australian Open fourth-round meeting, which three-time Grand Slam finalist Zverev won 6-3 6-4 6-4 on his way to the Melbourne final.

The physical and mental toughness Fearnley showed to beat Bonzi was impressive.

Fearnley needed a medical timeout before the deciding set, laying out on the court for treatment in the left hip area.

While he lost serve in the opening game, the Briton recovered the break instantly as more aggressive returning and going for his shots paid off.

“It was extremely difficult, I was feeling my left leg twitching a bit but I had to dig deep,” Fearnley told Sky Sports.

“I wanted no part of a rally so I was either missing it or hitting a winner. I had to go for it.”

Women’s third seed Coco Gauff thrashed fellow American Sofia Kenin 6-0 6-0 to progress to the third round in Miami.

The former US Open champion, 21, won 84% of her first-serve points, saved the one break point she faced and converted six of nine break points in the 47-minute stroll.

Women’s world number one Aryna Sabalenka responded to her surprise defeat in the final of Indian Wells last week with a 6-3 6-0 victory against Bulgaria’s Viktoriya Tomova.

Former Wimbledon champion Elena Rybakina, though, suffered a 4-6 6-2 4-6 defeat to unseeded American Ashlyn Krueger, as the seventh seed continued her mixed start to the year.