A near 'unraceable' surface has helped Irish galloper Allegio record the biggest winning margin in a Flat handicap in Ireland or Britain over the past two decades in a race at Cork on Sunday. 

Allegio ploughed his way through the very heavy going to record a remarkable 33-length victory in a 1700m handicap. 

Starting the $3.25 favourite in the field of four, the son of Galileo held a margin of just three lengths at the 600m before extending the margin with every stride down the straight. 

As much as Allegio was relishing the wet conditions, his rivals were having a nightmare in the rain-sodden surface, seemingly going up and down in the one spot. 

Aussie Valentine ($7) eventually crossed in second place, finishing a short head in front of Saltonstall ($4). 

The winning time for the 1700m was 2:12.76 seconds, with Allegio coming home in a tick over 16 seconds for the final furlong. 

 Allegio's trainer Denis Hogan told Irish Racing he initially thought the Galileo gelding would be better suited on firm surfaces. 

"I know it was only four runners but they have to go through the ground. Last year we thought he was a good ground horse but he has turned inside out over the winter," Hogan said. 

"Seamie (Heffernan) said all last year he was on the weak side."

""I'm not sure where we go from here but he is very good and I think the handicapper can't be as harsh as the winning distance because the others couldn't go."

It was Allegio's second straight victory on a heavy track at Cork, having won by six lengths in a 2000m race back on March 31. 

It wasn't the only race on the card that produced a big margin after three-year-old debutant Expected swam his way to a crushing 21-length victory in the first of the day. 

There were concerns post-race that the meeting would have to be abandoned after jockey Colm O'Donoghue, who was aboard distant runner-up Escapability, told stewards he felt the track was unraceable.

Stewards interviewed the Clerk of the Course who stated that in his opinion the ground was consistently heavy and that racing could proceed

Having considered both opinions, the Stewards were satisfied the meeting could go ahead.