Jackie Stewart won his second race in succession, but the Spanish Grand Prix will be best remembered for two almost identical crashes involving the Lotuses of Graham Hill and Jochen Rindt which could have left either dead. That they escaped with minor injuries was purely down to luck.
What was in no doubt was that the Lotus was a fast car, but Rindt complained the speed came at the cost of safety, something he repeatedly made clear to Colin Chapman. However, both occupied the front row of the grid at the new Montjuїc circuit in Barcelona.
Rindt led the field away with Chris Amon getting his Ferrari in between the Lotuses. For nine laps all was well, but then Hill's car violently veered into the Armco barriers. Several teams had decided to mount the wings on high supports attached to the suspension uprights - at both the front and the rear - and Lotus had fitted the largest rear wings, to such an extent that it created too much downforce for the uprights to handle. Witnesses and Hill himself said the rear wing had collapsed, making the car uncontrollable. He walked away shaken but unharmed.
Rindt continued only for exactly the same thing to happen to him in the same place 11 laps later. His car smashed into the barriers and then hit the wreckage of Hill's and flipped a dozen feet in the air before landing upside down. He too was incredibly fortunate, sustaining no more than superficial face wounds and a broken nose. Hill was still at the site of his mishap and helped pull his unconscious team-mate clear.
That left Amon ahead of Jo Siffert with Stewart in third, and he moved up into second when Siffert's engine sprung an oil leak. By the 57th lap Amon was a minute clear but, almost inevitably, the elusive victory again disappeared when the engine on his Ferrari blew and he skewed to a halt in front of the pits.
Stewart had quietly moved from sixth to first without having to overtake a car and was only one of five drivers to complete the race, and the only one to go the full distance. In view of what had happened earlier, Jacky Ickx had a lucky escape as well when his rear wing started disintegrating, shedding parts onto the track, but he was able to pit and resume to take sixth.
While Stewart celebrated, the fall-out from the Lotus accidents had started and the FIA immediately announced a special meeting to discuss the use of the wings. By the time the teams reassembled in Monaco a fortnight later they had been banned.