US Open, Day 2 roundup: Murray impresses, win for Serena

Murray showed his fight as he dug deep to seal a 4-6, 4-6, 7-6 (7/5), 7-6 (7/4), 6-4 victory against Nishioka.

"That's by far the most tennis I've played since 2019," said Murray, who had previously lost in five sets in the first round of the 2019 Australian Open to Roberto Bautista Agut.

Russian third seed Medvedev brushed past Argentina's Federico Delbonis 6-1, 6-2, 6-4 in an evening match at Arthur Ashe Stadium.

Meanwhile, Thiem, who was leading 7-6 (8/6), 6-3 against Jaume Munar, progressed after the latter retired.

14th seed Grigor Dimitrov thumped Tommy Paul 6-4, 6-3, 6-1.

Croatia's Marin Cilic required five sets to oust American Denis Kudla 6-7 (3/7), 3-6, 7-5, 7-5, 6-3.

Veteran 38-year-old Serena Williams powered past Kristie Ahn 7-5, 6-3.

Serena smashed 13 aces as she dispatched Ahn in one hour 21 minutes.

She smashed a new record of clinching the most singles victories in US Open history (102).

Meanwhile, Serena's elder sister Venus, who made her record 22nd appearance at the US open, was ousted by Karolina Muchova 3-6, 5-7.

Kim Clijsters, who was playing her first Grand Slam match in eight years, was beaten in three sets by Ekaterina Alexandrova 6-3, 5-7, 1-6.

Sofia Kenin advanced to the second round with a straight-set win over Yanina Wickmayer.

Tenth seed Garbine Muguruza enjoyed a 6-4, 6-4 victory over Japan's Nao Havino.

Victoria Azarenka had an easy outing against Austria's Barbara Haas 6-1, 6-2.