First-seeded David Ferrer advanced to the second round of the Mexican Open with a convincing win over Kazakh Mikhail Kukushkin while American and third-seeded John Isner became the first major casualty of the tournament, losing 7-6 (4) 7-6 (5) to Croatia's Ivo Karlovic on Tuesday.
Ferrer, who is trying to win on Mexican soil for the fourth time in his career, defeated Kukushkin 6-2, 6-3 and will play Spanish compatriot Feliciano Lopez in the round of 16.
"I*m not thinking about the final, I'm only in the second round", Ferrer said. "Now I'm only thinking about playing my best tennis against Feliciano Lopez, he*s a good player I need to give my best to beat him".
Ferrer, who now has a 4-0 record against Kukushkin, is coming off an impressive run in the past two weeks of the ATP tour, winning the Buenos Aires tournament and reaching the semifinals in Rio de Janeiro last week.
"Playing in Buenos Aires was not in my plans", said Ferrer who replaced his countryman Rafael Nadal in Argentina. "I'm tired, but I will not be making any excuses, I need to take a rest now and get well for the rest of the tournament".
Karlovic served 15 aces to Isner fired eight in a match between two of the game's biggest servers.
"I'm very disappointed," a visibly upset Isner said after the match. "I wanted to do well in here, is a good surface for me, but I played against a guy who played well against me".
The 2.11-meter (6-foot-11) Karlovic now has a 3-2 career record against the 2.08-meter (6-foot-10) Isner, who's ranked 13th in the world.
Joao Sousa of Portugal came back to defeat Frenchman Adrian Mannarino 1-6, 6-2, 6-2 to advance to a second-round encounter against the winner of the later match between Andy Murray and Pablo Andujar.
South Africa's Kevin Anderson downed Stephane Robert of France 6-2, 7-6 (7) and will next play America's Sam Querrey. Also, Alexandr Dolgopolov, from the Ukraine, beat Canada's Vasek Pospisil 6-2, 6-2 and seventh-seeded Ernests Gulbis had a 6-1, 6-1 victory over Taiwan's Yen-Hsun Lu.
Latvia's Gulbis won his fifth career title last week in Marsella.
On the women's side of the combined ATP-WTA tournament, top-seeded Dominika Cibulkova had a 6-3, 6-4 win over Urszula Radwanska, from Poland, and China's Shuai Zhang came back to beat Madison Keys of the United States 4-6, 6-1, 6-4.