Mexico City - Rafael Nadal is back in action for the first time since his Australian Open quarter-final exit, heading the field at the Mexico Open in Acapulco.
A two-time former champion of the tournament, Nadal was knocked out in the second round last year by mercurial Australian Nick Kyrgios in a match that sparked angry words between the two.
Nadal accused Kyrgios of "lacking respect" after he served underarm in their 2019 clash, but the Spaniard said on Monday he felt no lingering resentment.
"Last year, I lost a tight match that I should have won, but it's part of our sport and I don't have a bad memory of that," Nadal said.
"I have never had a feeling of revenge, no feeling of revenge helps you win games, but the opposite," he added. "The only thing that revenge does is that you can not think clearly."
World No 2 Nadal has a chance to return to the top of the rankings this week - if he lifts the trophy and Novak Djokovic fails to reach the semi-finals in Dubai.
Nadal will open his Acapulco campaign on Tuesday against 54th-ranked compatriot Pablo Andujar.
"We know each other well, we played since we were 13 or 14 years old, he is a good friend," Nadal said. "The first games are always complicated, but I'm looking forward to doing well."
Kyrgios, seeded sixth and in the opposite half of the draw from Nadal, opens on Tuesday against France's Ugo Humbert.
Results on Monday in the ATP and WTA tournament in Acapulco (x-denotes seeded player):
Miomir Kecmanovic (SRB) bt Alex De Minaur (AUS) 3-6, 6-4, 6-3
Stan Wawrinka (SUI x3) bt Frances Tiafoe (USA) 6-3, 6-7 (4/7), 7-6 (7/1)
Adrian Mannarino (FRA) bt Cameron Norrie (GBR) 2-6, 6-3, 6-3
Marcos Giron (USA) bt Gerardo Lopez (MEX) 6-4, 7-6 (7/3)
Tommy Paul (USA) bt Mackenzie McDonald (USA) 6-7 (4/7), 6-4, 6-4
Tamara Zidansek (SLO) bt Anna Kalinskaya (RUS) 6-3, 6-4
Tatjana Maria (GER) bt Marie Bouzkova (CZE x3) 6-4, 1-6, 6-2
Anastasia Potapova (RUS) bt Anna Karolina Schmiedlova (SVK) 4-6, 7-5, 6-1
Nao Hibino (JPN x8) bt Arantxa Rus (NED) 6-3, 6-1
Heather Watson (GBR x7) bt CoCo Vandeweghe (USA) 4-6, 6-4, 6-4
Kateryna Bondarenko (UKR) bt Danka Kovinic (MNE) 6-7 (7/9), 6-4, 6-2
Wang Xiyu (CHN) bt Wang Yafan (CHN x2) 6-4, 7-6 (10/8)