Juan Martin del Potro continued his perfect record against Kevin Anderson, winning the Mexican Open final in Acapulco on Saturday.
The Argentinian broke once in each set on his way to a 6-4 6-4 victory over Anderson after one hour and 40 minutes.
The success marked Del Potro's 21st ATP World Tour title as he improved to a perfect 7-0 head-to-head against Anderson.
For Anderson, it was the second time he has finished as runner-up in Mexico, having also lost the final in 2014.
Del Potro served 12 aces and did not face a break point, breaks of serve midway through the first set and early in the second proving decisive.
Despite his defeat, Anderson has enjoyed a fine start to the year, with his final marking his third of 2018.