Rafael Nadal accused Nick Kyrgios of lacking respect after a dramatic loss to the controversial Australian in the second round of the ATP Tour event in Acapulco.

Kyrgios fought from a set down and then saved three match points after trailing 6-3 in the deciding tie-break, storming back to win 3-6 7-6 (2) 7-6 (6).

The 23-year-old claimed he was considering retiring after the first set because of nausea but carried on because he did not want to deal with the reaction. He was then booed for attempting an underarm serve, and the handshake at the end was distinctly brief.

Speaking at his press conference, Nadal told reporters: "He is a player who has enormous talent. He could win grand slams and fight for the top positions of the ranking, but there is a reason why he is where he is. He lacks respect for the public, the rival and towards himself."

Kyrgios has slipped to 72nd in the rankings after a difficult start to the season but this was his third win in six meetings with Nadal, and he made clear the Spaniard's opinion does not interest him.

"I'm different, Rafa's different," Kyrgios told reporters in Mexico. "He can focus on what he needs to do. He doesn't know the journey I've been through, doesn't know anything about me, so I'm not going to listen at all."

At the Brasil Open, Felix Auger-Aliassime knocked out fifth seed and three-time champion Pablo Cuevas in the opening round.

The Canadian teenager, who reached his first ATP Tour final in Rio last weekend, saved four of the five break points he faced to claim a 5-7 6-3 6-3 victory.

The man who beat him on Sunday, Serbia's Laslo Djere, also clinched a first-round win, defeating Italian qualifier Alessandro Giannessi 7-6 (5) 4-6 6-4, while Christian Garin, Leonardo Mayer, Guido Pella and Marco Trungelliti reached the quarter-finals.