Kei Nishikori has booked his place in the quarter-finals of the Mexican Open courtesy of a 6-1 6-3 victory over Lu Yen-hsun in Acapulco.
The top seed held serve in the opening set, breaking his opponent on two occasions to race ahead.
It was a similar story in the second, where despite losing serve in the fourth game the Japanese star still managed to run away with the contest, capitalising on five of his six break chances and hitting 16 winners to advance through with relative ease.
Nishikori will now face fifth seed Alexandr Dolgopolov in the last eight of the competition.
