Rafael Nadal accused Nick Kyrgios of lacking respect after he was beaten by the Australian at the Mexican Open.

The former world number one passed up three match points before going down 3-6 7-6 (7-2) 7-6 (8-6) in an enthralling encounter in Acapulco on Wednesday.

But one incident, which saw Kyrgios serve when his opponent seemingly was not ready, appeared to irk Nadal and he shared only a brief handshake with the victor at the net.

Concluding his news conference afterwards, Nadal praised Kyrgios' talent but then questioned his attitude.

"He is a player who has huge talent, who could be winning Grand Slams or fighting for first position in the rankings," Nadal said.

The Spaniard added: "He lacks respect for the public, the opponent and himself."

Kyrgios took the opportunity to defend himself, though, saying Nadal "doesn't know anything about me" and suggesting the rules sided with him on the late flash point.

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

"That's the way I play. That's the way he plays. He's very slow between points and the rule of the book says you have to play at the speed of the server. Rafa has the speed every time.

"I'm not going to comment on him and his game. I've got my game, he's got his own game. We played well. That's the sport. People are different.

"I'm not going to take [the criticism] into consideration at all."