Emergency crews were dispatched to the scene in Myrniong following reports a car had lost control and flipped on the busy roadway about 6.30pm. 

Two primary school aged boys were taken by road to The Royal Children's Hospital in stable conditions, an Ambulance Victoria spokeswoman said.

“One of the boys had cuts and the other boy had minor neck injuries,” she said.

A man in his 40s was taken to the Royal Melbourne Hospital in a stable condition with shoulder injuries.

A witness said he saw traffic banking up in the Melbourne-bound lanes in the moments after the crash.

“I was driving home from Melbourne, just coming into Pykes Creek, there was a little car that had run off the road,” he said.

“There was really bad traffic and five ambulances went past me as I approached the smash.”

It was a busy night for emergency crews across the Ballarat region, with paramedics attending another rollover later in the night at Lal Lal.