The second seed celebrated his 27th birthday with a commanding 6-3, 6-3, 6-2 victory. Austrian Thiem, still seeking his maiden Grand Slam title, won an overwhelming 74% of his first serve points and fired seven aces past the inexperienced Nagal, breaking him seven times in the two-hour contest. Nagal became on Tuesday the first Indian in seven years to win a singles match at Flushing Meadows but the 23-year-old showed only flashes of brilliance in a one-sided clash at Arthur Ashe Stadium. Up next for Thiem, who was runner-up at the Australian Open this year, is 2014 champion Marin Cilic of Croatia who beat Slovakia's Norbert Gombos 6-3, 1-6, 7-6(2), 7-5. Daniil Medvedev charged into the third round with a 6-3 6-2 6-4 demolition of Australian battler Christopher O'Connell on Thursday. The Russian third seed, beaten by Rafa Nadal in last year's classic final, broke 116th-ranked O'Connell four times while giving him nothing on serve under a closed roof at Louis Armstrong Stadium. O'Connell, who cleaned boats in Sydney to make ends meet while injuries hampered his tennis aspirations, took a lengthy medical time-out to have a trainer work on an apparent back strain at 4-1 in the second set. The 26-year-old dug in admirably in the final set, prising his only two break points from the Russian, but Medvedev saved them and sealed the match with a big serve. Medvedev next faces young American J.J. Wolf for a place in the last 16. Eleswhere, Canadian Felix Auger-Aliassime proved too strong for former champion Andy Murray, cutting short the Briton's Grand Slam comeback at the US Open with a breezy 6-2 6-3 6-4 victory in the second round on Thursday. In the next round, Auger-Aliassime will meet either Frenchman Corentin Moutet or Briton Daniel Evans, who was serving to stay in the third set at 6-4 3-6 5-6 when rain stopped play on the outer courts.