It will take a Sherman tank to stop Rafael Nadal at this French Open. And, while the 5ft 7in Diego Schwartzman, the smallest man on the Tour, has many fine qualities, he is more akin to a sniper than someone coming into his quarter-final bearing heavy artillery.

In their five matches the world No 12 has taken one set – perhaps encouragingly, when they last met in a grand slam tournament, at the Australian Open this year. But this is clay. In Paris. Nobody messes with Nadal at Roland Garros – his “second home”, as Schwartzman described it.

Maximilian Marterer tried but he, too, was underpowered. He could bring only his racket and his heart on to Court Philippe-Chatrier, leaving sated but chastened after a first meeting with the Spanish master that lasted two and a half hours on Monday.

Seven women’s three-setters have gone longer than that in the first eight days and, after accounting for the young German, 6-3, 6-2, 7-6 (4), Nadal advances with only nine hours and 48 minutes on the clock.

While Nadal was grinding the estimable Marterer into the dirt on the main court Schwartzman was taking nearly four hours to beat Kevin Anderson on Court Suzanne-Lenglen. He could hardly have started more disastrously, winning three games in the first two sets, which sped by in 69 minutes. Then the fight began; he resisted then outlasted the 6ft 8in South African with sheer willpower. Anderson, who lost to Nadal in the US Open final last year, served for the match in the third and fourth sets but could not subdue the Argentinian. Schwartzman took the fourth-set tiebreak without losing a point before winning the fifth 6-2.

Diego Schwartzmann celebrates his five-set win over Kevin Anderson. Photograph: Caroline Blumberg/EPA

“I’m not sure how I did that,” Schwartzman said. “I am saying that and repeating it, because I really don’t know how I did it.” But did he believe he could beat Nadal on Wednesday? “Always. Always I believe. I need to recover well.” There is not much serious discussion here – outside the supporters of the players left in the draw – about Nadal falling short of winning an 11th title but Schwartzman could at least make it difficult for him.

Marterer had his moments but discovered even minor successes against the Spaniard should be cherished because they often count for little at the end. In the opening game he was given false hope. The German – who lost against Cameron Norrie in Lyon – got two break points when he hammered the net cord and it spilled over; he was even more grateful when Nadal served a double-fault. It was a dream start.

Marterer, a 22-year-old left-hander who looks as if he has spent a few hours in the gym, has raw rather than easy power and thrashed his way from deep to 2-0 after six minutes. Clearly he was enjoying himself. Nadal, never one to take even a point for granted, suspected he might have a fight on his hands. He looked relieved to hold.

Marterer’s CV is in its early stages at this level. Before reaching the third round in Melbourne this year he had lost all his 14 Tour-level matches. Here, three places below his career-best ranking of 67, he beat Ryan Harrison and the 24th seed, Denis Shapovalov, as well as the lucky loser Jürgen Zopp.

Maximilian Marterer feels the pain against Rafael Nadal. Photograph: Juergen Hasenkopf/BPI/REX/Shutterstock

But none of that could prepare him for a fist-pumping backlash by Nadal. The underdog had the crowd with him for a while, not because they wanted their Spanish favourite to lose but they craved a contest.

More than age separated Marterer and Nadal, who turned 32 this week: the 10-times champion has played nearly 10 times as many tie-breaks, 359, as Marterer has matches, 37. Nevertheless he had to save two break points for a 3-2 lead after 26 minutes.

And that was about the time the heat of battle – from the beating sun and Nadal’s still wicked top-spun forehand – started to take its toll on Marterer. He was exasperated as he could only watch a howitzer fly past him for another break. When he buried a backhand 10 minutes later the set he had started so promisingly had gone.

In the second Marterer lived on scraps, the odd mishit by his tormentor, his own occasional high-risk winner, to stay in touch. After a flicker of resistance mid-set there was not much menace left in his strokes and Nadal, hitting as hard as if it were the final, could smell victory. However, while witnesses to the slow slaughter in the sun were waiting for the main course – Serena and Maria, Pt22 (cancelled) – Marterer came to life again.

“If he hits a forehand like, really heavy, it’s something different compared to any other opponent,” Marterer said. He had to watch nine of them go past him in the third set (22 in the whole match). He broke once and saved on his own serve, but could not hold Nadal off in the tie-break. The fire in the champion’s eyes forged over 899 previous tour wins shouted that he was going to finish it right here for win No 900 – and he did.

“I suffered with a tough third set,” Nadal conceded. All things are relative.