Alex de Minaur has survived a hail of winners from powerhouse Jan-Lennard Struff with the passionate backing of a young fan to become the first Australian man for 17 years to reach the French Open singles last 16. The world No 11 emerged the stronger after a four-and-a-half hour rain stoppage to win 4-6, 6-4, 6-3, 6-3 on Saturday, clinching a breakthrough fourth-round appearance at Roland Garros.

De Minaur hailed his backs-to-the-wall triumph against an inspired big-hitting opponent and in the face of another mentally draining rain delay as one of the best of his career. The Australian also saved special mention for a young fan who helped will him over the line in the four-set battle with Struff.

The 25-year-old pointed to the fan and acknowledged him with fist pumps as he slowly turned around an early deficit against Struff. Then after sealing the comeback victory and shaking hands with Struff and the chair umpire, De Minaur went to the fan and shared a hug over the fence.

“That young lad was there from the very first point until the last with five hours of rain delay,” De Minaur said. “He was this little kid that every single change of ends, every single point I won, he was screaming at my face.

“I’m looking at him and thinking ‘if I was a fan, I would probably be back home, because it was bloody cold out there’. I don’t understand what this kid is doing, but he gave me life. Every single change of ends I’m looking at him, locking eyes with him.

“It was amazing. I appreciate this kid. The fact that he’s spent 10 hours at the court today in the freezing cold, pumping me up. I was happy that I was able to get a win together with him.”

After yet another late-night thriller, though, Thanasi Kokkinakis was unable to make it two Australian men into the fourth round for the first time since 2001 when his brave effort at a third five-set comeback in five days fell just short in a dramatic 6-3, 6-2, 6-7 (4-7), 5-7, 6-3 defeat to American 12th seed Taylor Fritz. It meant that, yet again, de Minaur is the last Aussie standing among the 11 singles entries.

“Another huge mental battle – it was probably one of my best performances, mentally, in my career to turn that match around with the conditions, with everything really against me,” de Minaur said.

“Everything couldn’t get any worse, right? I knew that this was just his [Struff’s] ideal conditions to a T. Slow, heavy, rainy, muddy, he’s able to hit through the court and not make a lot of mistakes.

“I told myself the only way I was going to win was just to fight until the end, fight every single point, keep battling, try to stay in no matter what. That’s what got me the win.”

De Minaur can consider the day he defused Struff’s thunderous game in six minutes under three hours in front of a largely pro-German crowd to make the second week in his least productive grand slam to be another key moment in his burgeoning career. He fought back to take the second set but was 2-0 down in the third when the rains came for the fifth straight day.

The Aussie No 1 had complained the constant interruptions to matches in the cold, damp conditions had added years to his life. But it was the booming groundstrokes of world No 41 Struff which had looked better designed to give him grey hairs, as he crashed 32 winners past the 11th seed even before the stoppage. It proved a timely one for de Minaur, as Struff admitted.

“After the rain, I felt he came on very well, played a bit more aggressive. At the end, he was playing very good, hitting very deep balls, getting into offensive positions,” Struff said. “He did a great job.”

De Minaur, at 3-1 down in the third, reeled off five games, and a break in the third game of the fourth was crucial, though de Minaur did suffer some nervous moments as Struff had two break points to get back on serve at 4-4. But de Minaur wouldn’t be denied, and, afterwards rushed over to hug the young fan at courtside who had been a non-stop cheerleader on this longest day. Now he can ponder the prospect of a fourth-round date with old foe, fifth seed Daniil Medvedev, who overcame Czech Tomas Machac 7-6 (7-4) 7-5 1-6 6-4.