The expertise of Irish champion jumps jockey Ruby Walsh has lifted Bashboy to a record breaking third Grand National Steeplechase success.

The Ciaron Maher trained 12-year-old carried 74.5kg, the highest weight since Pedro's Pride in 1957.

Bashboy also became the first horse to top the $1 million mark in prize money won over jumps with Sunday's victory over 4500m at Ballarat.

Walsh was called on to replace Steve Pateman, a winner of 12 races aboard Bashboy, after the latter failed in a careless riding appeal.

The Grand National was originally to be run at Ballarat on July 26, but a rain sodden track forced the postponement of the race until Sunday.

Not that Maher was concerned as it allowed him some extra time, and a schooling session at Cranbourne, to have Bashboy in peak condition.

"It was a real bonus that the race was put back," Maher said.

"He's just thrived, his coat has come out and he got the conditions to suit today."

Bashboy and runner-up, Thubiaan (Richard Eynon) who was chasing a $300,000 bonus after victories in the Brierly Steeplechase and Australian Steeplechases in May, had singled out from the opposition before the turn.

Both put in bad jumps at the second last with Thubiaan almost falling and Bashboy almost unseating Walsh, but the pair recovered and jumped the last in unison.

Bashboy landed better and under hard riding from Walsh scored by a half-length from Thubiaan with No Song No Supper 10 lengths away third.

"Jumping the second-last I thought we were going to run second again, but the horse and Ruby rallied again," Maher said.

Maher said it was a coup for Walsh to come to Ballarat to ride Bashboy and gave jumps racing scene an added shot in the arm.

Bashboy will now head to the spelling paddock before coming back to try for a fourth victory in the Grand National next year, before compulsory retirement at the age of 13.

Walsh says it's a pity the gelding will retire at the end of the season.

"He's 12, but he doesn't ride like a 12-year-old," Walsh said.

"He's a gem and has loads of running left in those legs."

With the retirement this year of Tony McCoy, Walsh has assumed the the title of the world's best jumps rider.

It will be a brief visit with the superstar jockey to return home on Monday.