There were a package of new regulations which outlawed the in-vogue high airboxes and reduced the size of the rear wings. Ferrari arrived with the new 312T2 which featured air ducts around the side of the cockpit. Ensign also had a new car. The major talking point, however, was the six-wheeled Tyrrell P34 one of which had been entered for Patrick Depailler. Team Lotus had dropped Bob Evans and Mario Andretti appeared alongside Gunnar Nilsson following Parnelli's decision to withdraw from F1. The field was boosted by the appearance of the RAM Brabham team with drivers Loris Kessel and Emilio de Villota and a third Williams which was entered for local hero Emilio Zapico. There was also a car called the Boro, which was little more than an old Ensign with another name. It was driven by Australian Larry Perkins. With only 24 starters there would be six non-qualifiers, including both RAM Brabhams, Brett Lunger's Surtees, Zapico, Harald Ertl's Hesketh and Ingo Hoffmann in the second Fittipaldi.

Qualifying resulted in James Hunt (McLaren) just beating Niki Lauda (Ferrari). Then came Depailler's Tyrrell, Jochen Mass's McLaren and Clay Regazzoni in the second Ferrari which shared the third row with Vittorio Brambilla's March. The fourth row featured Nilsson and Jacques Laffite (Ligier) with the top 10 completed by Andretti and Chris Amon, going well in the Ensign.

Lauda once again beat Hunt to the first corner with the fast-starting Brambilla third ahead of Depailler and Mass. The Beta March driver could not hold on to the position and drifted behind both Depailler and Mass in the early laps and on the 12th lap also fell behind Laffite. Both men would disappear soon afterwards leaving Nilsson to move to fifth. This became fourth on the 26th lap when Depailler spun out with brake problems.

At the front Hunt closed in on Lauda and on lap 32 the Englishman took the lead. Two laps later Mass was also ahead of the Ferrari and McLaren looked to be on course for a 1-2 result until lap 66 when Mass retired with an engine failure. This promoted Nilsson to third with Carlos Reutemann fourth in his Brabham-Alfa Romeo, Chris Amon fifth in the Ensign and Carlos Pace sixth in the second Brabham-Alfa Romeo.

After the race there was controversy when Hunt's McLaren was found to be too wide. The McLaren team argued that this had been caused by the expansion of the tyres during the race and appealed. It was not until July that Hunt was reinstated, although the team was fined $3000 by the FIA.