The British No 2, who climbed 17 places from 56 to 39 in the ATP world rankings earlier this week after his appearance in the final of the Croatian indoor championship, was rarely troubled by his Mexican opponent and won 6-3, 6-4.
Further victories in California could see Rusedski, who is seeded No 7 in San Jose, rise above his highest-ever world ranking of 33, which he achieved in January last year.
Rusedski later tasted further success in the first round of the doubles with his German playing partner, Alex Radulescu. They recorded a straight- sets victory over Sweden's David Ekerot and the American Jeff Tarango, winning 7-5, 6-3.
Steffi Graf, who has been troubled by a knee injury, has withdrawn from next week's WTA tournament in Hanover and may also miss Germany's Fed Cup match against the Czech Republic next month.
"I very much regret that I can't play in Hanover, but I have to first allow the injury that appeared in Tokyo to heal completely," Graf said.
Graf, who has been forced to stop all training, had to withdraw from the Toray Pan Pacific Open two weeks ago because of a severely aggravated patella tendon of the left knee, at the bottom front of the kneecap. She saw her doctor in Heidelberg yesterday.
The knee problem first troubled Graf in June while she was preparing for Wimbledon. In October she was forced to withdraw in the semi-finals at Leipzig because of it.
The German's appearance in the Fed Cup match early next month depends on the results of another examination next week.
A spokesman for Graf said: "What's important is that Steffi is completely healthy and can appear pain-free at further Grand Slam tournaments this year."
Britain is guaranteed a finalist in the LTA women's satellite event in Birmingham, with Shirli-Ann Siddall and Lucie Ahl meeting in the semi- finals today. In yesterday's quarter-finals Siddall thrashed Karen Cross 6-1, 6-2 and Ahl defeated the national junior champion, Louise Latimer, 6-4, 6-1. In the other semi-finalm Britain's Claire Taylor faces Tatiana Poutchek from Belarus.