Japan's Kei Nishikori cruised through his Shanghai Masters opener on Tuesday just 48 hours after lifting his second Tour title in Tokyo, as American John Isner saved three match points to progress.
Nishikori, the number 14 seed, who became the first Japanese player to win the Japan Open on Sunday, eased past China's Wu Di 6-2, 6-4 in his first round match.
"Obviously, it's not easy to play (so soon) after winning the tournament," said the 22-year-old, who is at career-high of number 15 in the rankings after his success in front of home fans.
"But I had a good day today. I love to play here," added Nishikori, who reached the semi-finals in Shanghai last year before he lost to eventual champion Andy Murray of Britain.
Nishikori's weekend win over big-serving Milos Raonic was his first on the Tour since the 2008 Delray Beach title, sharply raising expectations that Asia had uncovered a potential world-beater.
Eighth seed John Isner was forced to dig deep to save three match points to win a second-round match containing three tie-breaks and keep alive his outside chance to qualify for next month's ATP World Tour Finals.
Isner booked his place in the third round by beating South Africa's Kevin Anderson 7-6 (7/3), 6-7 (8/10), 7-6 (9/7) in two hours and 45 minutes.
In a match featuring 45 aces and no service breaks, Anderson squandered match points at 6-4 and 7-6 in the third set tie-break.
"Really we both served well," said Isner. "It's one of the few times where I don't think I was out served, but he served right up there with me as far as, you know, aces, percentages, whatnot."
"It came down to a few points here or there, and I was able to pull it out. It was looking bleak for a little bit," he added.
In first-round action, French 15th seed Gilles Simon knocked out Jurgen Melzer of Austria 6-4, 6-2 and Switzerland's Stanislas Wawrinka, the number 13 seed, battled past Albert Ramos of Spain 7-6 (7/1), 7-6 (7/5).
The top three seeds -- Roger Federer, Novak Djokovic and Murray -- all open their campaigns on Wednesday after first-round byes for the top eight seeds.