Tennis: Alexander Zverev to replace Jannik Sinner as ATP world number one after beating Tallon Girekspoor in Vienna

However, Cameron Norrie fell short of his best win of the season when world number five Daniil Medvedev saved a match point to win his round of 16 match.

A frustrating year has seen Norrie fall to 41st in the world rankings and exit each of the last three Grand Slam tournaments in the first round.

But the 31-year-old showed his key strengths – tenacity, athleticism and controlled aggression – to threaten to pull off a huge upset against Medvedev.

Third-seeded Medvedev, fresh from winning the Almaty title last week, found himself hitting the surface in anger when he broke down in the deciding set.

Norrie served for the match at 5-3 40-30, but Medvedev repelled his opponent’s serve-and-volley attempt and fought back to win 4-6 6-3 7-6 (7-1).

Second seed Alcaraz also advanced with a 6-1, 7-6 (13-11) win over Georgian Nikoloz Basilashvili.

Meanwhile, Novak Djokovic’s hopes of qualifying for the ATP Finals were dealt a blow by a second-round defeat at the Swiss Indoors event in Basel.

The 24-time major champion, 39, lost 7-6 (7-4) 5-7 6-7 (5-7) to German Jan-Lennard Struff, who produced inspired tennis to beat the Serb for the first time in nine attempts.