He finished 1.3 seconds ahead of British driver and Lauda's season long rival James Hunt in a McLaren M23.
Lauda led into the first corner, with Hunt dropping down to fourth behind Mass and Italian driver Vittorio Brambilla in his March 761.
Behind Hunt and Mass, South African driver Jody Scheckter was fourth in his Tyrrell 007.
A lap down in fifth was British driver John Watson in a Penske PC3 with Mario Andretti sixth in a Parnelli VPJ4B.
Two wins from two races saw Lauda twelve points clear in the championship over Hunt and Tyrrell's Patrick Depailler.