Haas was never troubled as he wrapped up a 6-2 6-1 win in 55 minutes, never facing a break point and dropping just one point on his first serve.
Lleyton Hewitt had a similarly easy day, the eighth-seeded Australian beating Bradley Klahn 6-3 6-1, but fourth seed Kevin Anderson had to come from a set down to beat Tim Smycek 4-6 6-1 6-3.
Former Australian Open finalist Marcos Baghdatis also survived a scare, the Cypriot beating Jiri Vesely of the Czech Republic 3-6 6-2 6-1.
Qualifier Steve Johnson ensured continued American representation with a 6-4 6-3 win over Mikhail Kukushkin while Ryan Harrison and Rhyne Williams advanced after their respective opponents Yen-Hsun Lu and Alejandro Falla pulled out due to injuries.
Williams was in control already at 6-3 4-0 but Harrison had dropped the first set before winning the opening game of the second.
Ivo Karlovic and Teymuraz Gabashvili enjoyed wins over Samuel Groth and Marcus Ebden respectively but Hewitt was at least joined in round two by one of his compatriots after Marinko Matosevic beat Belgium's David Goffin.
Dudi Sela was a comfortable 6-0 6-2 winner over Alex Bogomolov.