Rafael Nadal sealed his 12th consecutive win of the new season after a straight sets victory over Stefan Kozlov at the Mexican Open.
Nadal's 12-0 record to begin the year is the best of his illustrious career, and he never looked in any trouble as he eased to a 6-0, 6-3 win against the American to advance to the quarter-finals in Acapulco.
The Australian Open champion's next opponent will be Tommy Paul after he beat Dusan Lajovic 7-6 (8-6), 2-6, 7-5.
"A little bit of a strange match," Nadal said following his win. "Kozlov has a different style than most other players, so you need to be very careful. Sometimes you are able to win points in a row, but then if you start to play at his rhythm, it's very difficult because he has great control from the baseline and he's very smart."
Number one seed Daniil Medvedev is also safely through after comfortably defeating Pablo Andujar 6-1, 6-2, and he will now go up against Yoshihito Nishioka after his victory against Feliciano Lopez.
Other contenders
Stefanos Tsitsipas managed to finish his match against JJ Wolf in less than 48 minutes as he romped to a 6-0, 6-1 win, while his quarter-final opponent Marcos Giron had a much tougher time of it getting past eighth seed Pablo Carreno Busta 6-7 (7-9), 6-4, 7-6 (7-4).
Cameron Norrie also came from a set down to beat John Isner 6-7 (2-7), 6-3, 6-4, and the sixth seed will now face Peter Gojowczyk after the German received a walkover following his compatriot Alexander Zverev being "withdrawn" from the singles competition after attacking the umpire's chair at the end of his defeat in the doubles.
