Rafael Nadal set up a semi-final meeting with new world number one Daniil Medvedev after cruising past Tommy Paul 6-0, 7-6 (7-5) at the Mexican Open in Acapulco on Thursday.
The Spanish fourth seed, who won last month's Australian Open against Medvedev in a five-set epic for a record-breaking 21st Grand Slam title, beat the American in two hours and three minutes.
Nadal was at his tenacious best early, winning the first set 6-0 for the second consecutive match, before Paul hit back in the second.
The Spaniard dropped only 10 points in the opening set with errors creeping into his game early in the second set allowing Paul to get 2-1 up a break.
The pair exchanged a string of four games against serve, with Nadal breaking again with Paul serving for the set, before triumphing in the tie-break.
Top seed Medvedev secured his spot in the last four with a 6-2, 6-3 victory over Japan's Yoshihito Nishioka.
World number one
Medvedev, who will officially become world number one for the first time in his career next week after Novak Djokovic's loss to Jiri Vesely in Dubai, brushed aside the Japanese in one hour and 10 minutes.
The Russian sent down 12 aces and won 69 per cent on his first serve, while he converted six of eight break points across the match.
Third seed Stefanos Tsitsipas will meet Briton Cameron Norrie in the other semi-final after both triumphed on Thursday.
Tsitsipas won his quarter-final against Marcus Giron 6-3, 6-4 in one hour and 17 minutes, while sixth seed Norrie made light work of Peter Gojowczyk 6-1, 6-0.