Japan's Kei Nishikori, the highest ranked Asian player in ATP Tour history, opened his Indian Wells campaign with a 6-4, 6-4 win over Ryan Harrison on Saturday.
The US Open runner-up broke Harrison five times to advance to the third round of the WTA and ATP Masters hardcourt tournament.
"I broke him many times today and that was the key for today's match," Nishikori said.
The 25-year-old Nishikori, who is seeded fifth, advanced to the third round, where he will play Fernando Verdasco of Spain.
Nishikori came into Indian Wells having won last month in Memphis after reaching the quarter-finals at the Australian Open.
He also reached the finals in Acapulco and has reached the quarters in all four tournaments he has competed in this year.
It was the second match in a short period of time and just the second career ATP meeting between the two. Nishikori beat Harrison in three sets 3-6, 6-3, 6-4 in Memphis.
"It was different because it was indoors," Nishikori recalled of that encounter. "It was a long match. He played good, but I played well in the second set."
Saturday's second round match was equally entertaining.
Neither player was able to take command in the first set, combining for seven breaks of serve. Nishikori would eventually convert on his third set point.
He secured a break to open the second set and then clinched the victory on his second match point when Harrison hit a shot long.
Flavia Pennetta opened the defence of her WTA title by beating American Madison Brengle 6-4, 6-2 in second round action.
Pennetta, who turned 33 last month, clinched the victory with a crosscourt forehand winner in a match that lasted 75 minutes.
Last year, Italy's Pennetta dominated Poland's Agnieszka Radwanska 6-2, 6-1 to win the biggest title of her career in the California desert.
"Last year I played so well here. I have so many good memories," Pennetta said.
The world number 16 said she was nervous about launching her title defence.
"This morning I woke up and I was shaking a little bit. During the match I was trying to be focussed on what to do and not be rushed," she said.
Pennetta is also hoping to use this event as a springboard to success for the remainder of the year. She had a rough start to the season, but did reach the semi-finals in Dubai.
Brengle was coming off a 6-3, 6-0 victory over China's Zheng Sai-Sai in the first round.
In the third round, Pennetta will face either Taylor Townsend of the United States or Samantha Stosur of Australia.
In other women's matches involving seeded players, fifth seeded Serb Ana Ivanovic defeated Yulia Putintseva 6-3, 6-1 and Italy's Sara Errani, who is seeded 11th beat China's Zhu Lin 6-0, 4-6, 6-2.