The Williams of Carlos Sainz ground to a halt at the Albert Park pit entry during the third and final practice session, causing the first red flag of the F1 season.
The Spanish driver lost drive in his FW48, getting stuck and blocking the way back to the garages less than 15 minutes into FP3 in Melbourne.
Initially, a virtual safety car was declared with the pit entry closed, but that was eventually upgraded, costing the teams around eight minutes of running.
The session was already delayed by 20 minutes for barrier repairs at Turn 5 after a collision between two PREMA drivers in the F3 sprint saw that race abandoned.
The Williams car is thought to be significantly overweight, and the team missed the private shakedown in Barcelona prior to testing in Bahrain.
This latest development leaves the 31-year-old further on the backfoot at the campaign curtain raiser.
Soon after the session resumed, Kimi Antonelli put his Mercedes at the top of the timing board, ahead of the Ferrari of Lewis Hamilton.
