The 33-year-old Swiss continued his quest for a sixth crown in Flushing Meadows, improving to 24-1 at night on Arthur Ashe Stadium and 18-1 lifetime against Australians in Grand Slam play. His only defeat came on major debut to Patrick Rafter at Roland Garros 1999. Federer is now a career 54-1 in Grand Slam second round matches, with his lone loss coming at Wimbledon last year to Sergiy Stakhovsky.
The Basel native, playing in New York for a 15th consecutive year, won his 51st match of 2014. He is the second-oldest player to claim 50 or more victories in a single season in the past 30 years, having achieved the feat with a first-round win over Marinko Matosevic on Tuesday.
Groth, the hulking Australian who holds the record for the fastest serve recorded at 163mph, threw everything he had at Federer - and the ball just kept coming back. He topped out at 147mph against the five-time former champion to no avail; one of his quickest deliveries of the night in the first set, a 142mph bullet down the T, flashed back past him before his feet had found the court.