Juan Martín del Potro continued his perfect record against Kevin Anderson, winning the Mexican Open final in Acapulco on Saturday at the American's expense.
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.
Voegele can't halt Tsurenko's perfect run
In the women's draw Lesia Tsurenko continued her incredible record in Acapulco, defending her title with a three-set win over Stefanie Voegele.
The Ukrainian secured her fourth WTA Tour title and first of 2018 with a 5-7 7-6 (7-2) 6-2 victory over Voegele in the decider.
Tsurenko now holds a 15-3 win-loss record at the WTA International event, including 10 straight victories.
The 28-year-old had won four of her five meetings with Voegele and she improved on that record after a battle lasting two hours and 44 minutes.
Voegele, who was in her first WTA final, came from a break down to win the first set before taking a 4-2 lead in the second.
But Tsurenko rallied to level the match before proving too good in the deciding set.
She became the third player to defend the women's singles title at the tournament, joining Venus Williams (2009-10) and Sara Errani (2012-13).