The event fell just 706 attendees short of its all-time record of 302,000, set in 2022.
Despite repeated honking from another driver, the sleeping driver failed to wake up.
He had to be hospitalised after his blood oxygen level fell to the low 90s.
Charles Leclerc finished second, while Kimi Antonelli rounded out the podium in third place.
The Spyros incident has been called Singapore's worst industrial disaster.
The man he accosted had purposely avoided been recorded by CCTV cameras, he said.
The affected patch of vegetation measured approximately 10m by 10m, SCDF said.
Another casualty declined to the sent to the hospital, the area's MP said.
Part of the railing on the road divider also appeared to have been knocked down.
It was unclear what happened to the dog and why it had been presumed dead.