Fourth seed David Ferrer passed a potentially dangerous test as he saw off big-serving South African Kevin Anderson in the US Open first round.
Ferrer, seeded to meet Novak Djokovic in the semi-finals, was too versatile and consistent for 6ft 8ins Anderson, winning 6-4 6-2 7-6 (7-3).
The 2007 semi-finalist will next play Dutchman Igor Sijsling after he beat Daniel Gimeno-Traver 7-5 6-3 6-4.
Janko Tipsarevic beat Guillaume Rufin and John Isner overcame Xavier Malisse.
Eighth seed Tipsarevic came from two sets down to win 4-6 3-6 6-2 6-3 6-2 and set up a second-round meeting with Brian Baker.
Unseeded American Baker continued his remarkable post-injury rise with a 6-3 6-4 6-2 victory over Czech Jan Hajek.
Number nine seed Isner of the United States survived a fightback from Xavier Malisse to post a 6-3 7-6 (7-5) 5-7 7-6 (11-9).
Thirteenth seed Richard Gasquet lost the first set against Albert Montanes but bounced back to defeat the Spaniard 4-6 6-2 6-3 6-3 to set up a meeting with either Jurgen Melzer or Bradley Klahn.
Former world number one Lleyton Hewitt, the champion in 2001, lost in the first round last year but this time round he beat Germany's Tobias Kamke 4-6 6-2 6-1 6-4.
Next up for the Australian is Luxembourg's Gilles Muller, who fought back from two sets down to eliminate 28th seed Mikhail Youzhny 2-6 3-6 7-5 7-6 (8-6) 7-6 (8-6).
Another seed to falls was Viktor Troicki (29th) as he lost 4-6 4-6 6-3 2-6 to Germany's Cedrik-Marcel Stebe.