The Spaniard, who must lift the title on Sunday to remain as world No.1 next week, dominated his compatriot to set up a last eight meeting with Martin Klizan. The Slovakian earned a shot at the defending champion by nudging Feliciano Lopez aside 6-1 6-4.
Nadal has now won 40 consecutive sets in a row on clay – and his domination on the red dirt is unlikely to end anytime soon.
Malek Jaziri is almost certain to endure a difficult night’s sleep. The Tunisian squandered two match-points before eventually falling to Grigor Dimitrov after a ferocious battle that lasted ten minutes shy of three hours.
The Bulgarian prevailed 7-5 3-6 7-6(8) and will challenge Pablo Carreno Busta next, who shimmied past Adrian Mannarino 6-2 4-6 7-6(6).
Last year’s finalist, Dominic Thiem, remains on course for an eighth clay-court triumph after dispatching Josef Kovalik 7-6(5) 6-2. He will take on Stefanos Tsitsipas, who overcame Albert Ramos-Vinolas 6-4 7-5, for a place in the last four.
“I’m really happy that I went through, but for sure, it was not the best performance,” Thiem told the ATP website. “I didn’t feel that great on court today but I still managed to win.
“I’m proud that I did it in two sets, but the tennis game was not that great, I guess. My two performances so far have been medium, and there is obviously room for improvement.”
At the Budapest Open, John Millman defeated Lucas Pouille 6-3 6-4 to ensure his French opponent remains without a victory at ATP level since February.
Nikoloz Basilashvili got the better of Denis Shapovalov 6-2 6-4. The Canadian is far from comfortable on clay and it may be a difficult few months for the teenager.
Andreas Seppi and Yannick Maden are also through to the last eight.