I Am Maximus hs romped to a stunning victory in the Grand National steeplechase as trainer Willie Mullins continued his dominant jump-racing season in Britain and Ireland.

The 176th edition of the iconic race, watched by tens of thousands at the Aintree course in Liverpool and by millions more around the world, was still wide open as the last of the 30 fences was cleared on Saturday.

But 7-1 joint-favourite I Am Maximus, owned by Irish billionaire magnate JP McManus and ridden by top Irish jockey Paul Townend, produced a devastating burst of speed to leave the field trailing in his wake.

Delta Work (28-1) was second with Minella Indo, ridden by Rachael Blackmore, in third place.

One of the favourites, Corach Rambler, winner of last year's race, unseated his rider at the first fence.

Twenty one horses finished the race from the initial field of 32 with no reported casualties as new rules designed to enhance rider and horse safety were employed.

"What an unbelievable race and an unbelievable horse. It is a bit surreal, to be honest," Townend, who won the race for the first time in his career, said.

"I ended up being first to the first and got to the Melling Road and he backed back.

"Gold Cups and Grade Ones are special but Grand Nationals are different. You need so much luck. I am a lucky boy."

Last month the Mullins-trained Galopin Des Champs, also ridden by Townend, won the Cheltenham Gold Cup for the second year in succession. Mullins had not trained a Grand National winner since Hedgehunter in 2005.

"Paul Townend was super on him," Mullins said. "We saw last year in the Irish Grand National we had supreme confidence in the horse that he had a bit in the tank.

"He was biding his time and he delivered. I didn't say anything until the last fence but then I let go. I love it, I'm buzzing, it's huge."

There was no repeat of last year's disruption caused by animal rights protesters and organisers will be relieved that the new rules helped deliver a safe race.

The field was reduced from 40 to 34 horses while there was a standing start designed to reduce the speed going into the first fence which was brought forward by 60 yards. Fence 11 was also lowered in height.