Daly never actually led the race! Prost crashed on his 74th lap giving the lead to Patrese who retained it until he spun on entry to the hairpin on his 75th lap and stalled his engine. This gave the lead to Pironi who ran out of fuel a lap later in the tunnel on his 76th and final lap while de Cesaris, who would have inherited the lead, also ran out just before the tunnel and never passed Pironi. Daly’s gearbox gave up at Rascasse near the end of his 75th lap before he could come around and pass Pironi for the lead. Patrese meanwhile had straightened his car around and managed to bump start the engine while coasting down the hill to Portier. He then passed the stopped Pironi in the tunnel to unlap himself and continued on to start his final lap and pass Pironi in the tunnel again to take the lead and the win.
Daly was credited with having completed 74 laps. Pironi, de Cesaris, Mansell and de Angelis completed 75 laps. Only Patrese completed 76 laps. From the time Pironi passed Patrese in the hairpin on their 75th lap until Patrese passed the stopped Pironi in the tunnel for the second time on Patrese’s 76th lap, Pironi was the leader. Daly would have had to finish his 75th lap and then continued on his 76th lap to pass Pironi in the tunnel to ever have become the leader of the race.
Three leaders: Prost, Patrese and Pironi
Four Lead Changes: Prost->Patrese->Pironi->Patrese