The number one seeds were largely untroubled in their opener against the Cerundolo brothers, but Heliovaara and Patten were made to work hard for their first set win, as after failing to take a break point chance in game two, neither pair came close to losing serve as the Finn and Brit went 6-5 up.
But in the 12th game, the Wimbledon champions made a breakthrough, racing into a 40-0 lead before getting over the line with their second set point, taking it 7-5.
The favourites held off Arnaldi and Struff in the third game of the second set, and then hit back in the next to force a loss of serve and go 3-1 ahead.
Serving to stay in the match at 5-2 down, the Italian and German again struggled to contain Heliovaara and Patten when the finish line was in sight, as the Finnish-British pair secured match point at the first attempt for a 6-2 set victory, and a straight-sets win.
In the next round, Heliovaara and Patten will face the winner of the match between Americans Nathaniel Lammons & Jackson Withrow and Portuguese-American duo Francisco Cabral & JJ Tracy.