Rublev fired 15 aces to oust last year’s finalist Borna Coric, 6-4, 7-6 (4). After failing to serve out the match at 5-4 in the second set, Rublev regrouped in the tiebreaker to clinch the win over the No. 12 seed in one hour and 36 minutes. Coric will fall outside of the Top 20 as a result of his loss.
In a tough first-round matchup featuring two Top-25 players, No. 17 Isner edged No. 24 Alex de Minaur, 7-6 (1), 6-4. Isner had a big-serving day of his own, unleashing 18 aces. The 33-year-old, who did not face a break point, will next meet Lucas Pouille. The Frenchman rallied from a set and a break down to deny wild card Li Zhe his first ATP main draw win with a 6-7 (4), 6-4, 6-4 victory.
A week after losing to Andy Murray in Beijing, Matteo Berrettini bounced back with a convincing win. The US Open semifinalist needed just over an hour to dismiss Jan-Lennard Struff, 6-2, 6-1, breaking the German five times. Berrettini enters this week at No. 10 in the Race To London, as his loss to Murray enabled Alexander Zverev (reached Beijing semifinals) and David Goffin (reached Tokyo semifinals) to move ahead for the time being.
Coming off a final four showing in Tokyo, Reilly Opelka also advanced, defeating Dusan Lajovic, 6-3, 6-4. Opelka will take on eighth seed Roberto Bautista Agut in the second round.