Miami - Japanese sixth seed Kei Nishikori advanced to the third round of the ATP and WTA Miami Open on Saturday by defeating 107th-ranked French qualifier Pierre-Hugues Herbert 6-2, 7-6 (7/4).
The 26-year-old Asian star, runner-up at the 2014 US Open and coming off a fourth consecutive title last month at Memphis, denied the Frenchman on two set points in the ninth game of the second set and took four of the last five points in the tie-breaker to win after 88 minutes.
"He played much better in the second set," Nishikori said. "I tried to be aggressive. I knew I had to somehow give him some pressure. I stayed confident even a break down and had a good win."
Next up for Nishikori, who could meet Britain's Andy Murray in a quarter-final, is Ukraine's 27th-seeded Alexandr Dolgopolov, a 6-4, 6-4 winner over Italy's Andreas Seppi.
Nishikori broke twice at the start to seize a 4-0 lead and took the first set in 29 minutes, but Herbert saved a break point in the third game of the second set and hit a forehand crosscourt winner to break Nishikori for a 3-1 lead.
Herbert served for the set up 5-3 but squandered two set points, Nishikori hitting a forehand lob winner and Herbert sending a backhand wide before the Frenchman double faulted away a break.
In the tie-breaker, Nishikori sent a backhand long to level matters at 3-3 but dominated from there and finished on a service winner.
Czech eighth seed Petra Kvitova, a two-time Wimbledon champion, was eliminated by Russia's Ekaterina Makarova 6-4, 6-4. The 30th seed will next face either Danish 23rd seed Caroline Wozniacki or Ukraine's 12th-seeded Elina Svitolina.
Canadian 12th seed Milos Raonic, coming off a runner-up showing at Indian Wells, beat American Denis Kudla 7-6 (7/4), 6-4. He faces US 22nd seed Jack Sock or Ukraine's Sergiy Stakhovsky next.
World number one Serena Williams will try to reach the fourth round while second seed Murray and 14-time Grand Slam champion Rafael Nadal will open their title quests later at the hardcourt event.
Williams, coming off back-to-back finals losses for the first time since 2004 at the Australian Open and Indian Wells, meets 97th-ranked Kazak Zarina Diyas. The US star, a 21-time Slam winner, struggled in her three-set opening win over compatriot Christina McHale.
Murray, the 2012 US Open and 2013 Wimbledon champion, faces Uzbekistan's Denis Istomin, whom he beat twice in 2013 in their only prior meetings. The Scotsman won the Miami crown in 2009 and 2013 and was runner-up to Novak Djokovic in 2012 and 2015.
Istomin, who took his first victory of the year Thursday over Croatia's Borna Coric, is 1-29 against top-10 foes, having dropped 19 in a row.
Spanish fifth seed Nadal, a four-time finalist but never a champion at Miami, opens against Bosnia and Herzegovina's 94th-ranked Damir Dzumhur.
Scores on Saturday from the fifth day of the ATP and WTA Miami Open (x denotes seeded player):
Kei Nishikori (JPN x6) bt Pierre-Hugues Herbert (FRA) 6-2, 7-6 (7/4)
Alexandr Dolgopolov (UKR x27) bt Andreas Seppi (ITA) 6-4, 6-4
Milos Raonic (CAN x12) bt Denis Kudla (USA) 7-6 (7/4), 6-4
Ekaterina Makarova (RUS x30) bt Petra Kvitova (CZE x8) 6-4, 6-4
Svetlana Kuznetsova (RUS x15) bt Caroline Garcia (FRA) 4-6, 6-2, 7-6 (8/6)