World tennis No.1 Novak Djokovic, reigning US Open champion Marin Cilic and former winner Rafael Nadal all cruised into the third round of the final major of the year in New York.
Djokovic had no problems dispatching Austria's Andreas Haider-Maurer in straight sets, the Serb winning 6-4 6-1 6-2 on Arthur Ashe centre court.
Cilic was also untroubled, the Croatian ninth seed beating Russian Evgeny Donskoy 6-2 6-3 7-5.
Nadal was pushed slightly harder by Argentina's Diego Schwartzman before the Spanish great won 7-6 6-3 7-5.
Also progressing were seventh seed David Ferrer of Spain, who was pushed hard in each set by Serbia's Filip Krajinovic before winning 7-5 7-5 7-6, and 10th seeded Canadian Milos Raonic, who needed four sets to knock out Spanish veteran Fernando Verdasco.
Auckland-bound French star Jo-Wilfried Tsonga beat Spain's Marcel Granollers, while another Spaniard, the veteran Tommy Robredo, ended Australian Samuel Groth's run, also in straight sets.
Venus Williams also outlasted American compatriot Irina Falconi 6-3 6-7 6-2.
Grigor Dimitrov of Bulgaria was the day's biggest casualty, the 17th seed losing to Mikhail Kukushkin, the Kazakh triumphing in an epic five-setter, taking it 6-3 7-6 2-6 4-6 6-4.