Daniil Medvedev, in his first match since clinching the world number one ranking, beat Japan's Yoshihito Nishioka 6-2, 6-3 in Acapulco on Thursday to reach the semi-finals of the ATP 500 event where he could next face Rafael Nadal in an Australian Open final rematch.
Medvedev, who took the court hours after Novak Djokovic's quarter-final loss in Dubai meant the Russian would replace him atop the rankings, converted six break points and fired down 12 aces, including one to seal the match.
After blitzing his way through the first set, during which he converted all three break point chances and won 80% of his first serve points, Medvedev was forced to rally back in the second after falling behind 3-1.
Up next for Medvedev is Australian Open champion Nadal, who made a blistering start against world number 39 Tommy Paul but faced a second set fightback from the American amid increasing humidity to prevail 6-0, 7-6 (5).
Medvedev squandered a two-set lead against Nadal in their previous meeting in the Melbourne final in January, allowing the Spaniard to clinch his 21st Grand Slam title.
He will have to be in top form to beat Nadal, who is on a 13-match winning streak in 2022 - his best start to a season in his career at the age of 35.
Medvedev said it would be special to face Nadal again.
"Kind of a chance to get my revenge," said Medvedev.
"You have to learn from the best, which is him, Roger (Federer), Novak, Andy (Murray) ... always when they were losing a tough fight, they were trying to get their revenge."
"Sometimes they managed to win, sometimes not, and that's what I going to try to do if I play Rafa."
World number four Stefanos Tsitsipas, who was runner-up in Acapulco last year, also reached the semi-finals with a 6-3, 6-4 victory over American Marcos Giron and has not dropped a set this week.
Tsitsipas will face British sixth seed Cameron Norrie who lost just one game to hammer Germany's Peter Gojowczyk 6-1, 6-0 in the day's final match on the main show court.
Gojowczyk had received a walkover to the quarters after last year's champion Alexander Zverev was kicked out of the event for his assault on an umpire's chair.
In the women’s draw, fourth-seeded Camila Osorio of Colombia shook off a slow start to beat the United States' Hailey Baptiste 1-6, 6-3, 6-3 in the second round at Guadalajara, Mexico.
After Osorio put just 48 percent of her first serves in play during the opening set, she raised that figure to 58 percent in the second set and 80 percent in the third set.
The other seeded players in action won their second-round matches in straight sets. Third-seeded Sara Sorribes Tormo of Spain routed Poland's Magdalena Frech 6-0, 6-2, and sixth-seeded Sloane Stephens of the United States topped France's Chloe Paquet 7-5, 6-4. Another quarterfinal berth went to Australia's Daria Saville, who defeated the United States' Caroline Dolehide 6-1, 6-3.
Iga Swiatek storms into semifinals in Doha
No. 7 seed Iga Swiatek of Poland stormed into the semifinals with a 6-2, 6-3 victory over top-seeded Aryna Sabalenka of Belarus on Thursday at the Qatar TotalEnergies Open in Doha.
Swiatek converted seven of eight break points in the one-hour, 14-minute quarterfinal match. Up next is sixth-seeded Maria Sakkari of Greece, a 6-3, 6-3 winner over No. 14 Coco Gauff. Sakkari has won all three previous matches against Swiatek.
No. 4 Anett Kontaveit of Estonia and No. 15 Jelena Ostapenko of Latvia will meet in the other semi-final after their straight-set wins Thursday. Kontaveit defeated No. 8 Ons Jabeur of Tunisia 6-4, 6-1, and Ostapenko eliminated No. 5 Garbine Muguruza of Spain 6-2, 6-2.
Kontaveit has an eight-match winning streak and has won five titles in the past seven months, including two weeks ago at St. Petersburg. She is 3-1 against Ostapenko.