Rafael Nadal registered the best start to a season in his career as he breezed past Stefan Kozlov to reach the Mexican Open quarter-finals.
The Australian Open champion extended his unbeaten run to 12 matches with a 6-0 6-3 win over American Kozlov.
Nadal's previous best start to a season came in 2014, when he won 11 matches before losing to Stan Wawrinka in the Australian Open final.
He will play Tommy Paul for a place in the Acapulco semi-finals.
Nadal, 35, could then meet world number two Daniil Medvedev, who he beat in a thrilling Melbourne final in January.