Aidan O'Brien and Johnny Murtagh got the perfect start to Breeders' Cup 2009 by winning the opening Marathon with Man Of Iron at Santa Anita on Friday night.

The three-year-old Giant's Causeway colt, sent off at 13-2 just prevailed in a thrilling finish against the nine-year-old Cloudy's Knight (10-1). St Leger hero Mastery - sent off the 7-4 favourite - took third.

Murtagh settled Man Of Iron towards the rear of the field in the early stages, with the more fancied Mastery and Father Time sitting just off the front rank.

But Cloudy's Knight swept to the front rounding the top of the home stretch, with Frankie Dettori on Mastery giving chase.

But in behind them Murtagh had made stealthy progress on Man Of Iron and they were closing rapidly on the inside.

With a furlong to go it looked like the Ballydoyle colt might score cosily but Cloudy's Knight battled on really gamely and only just failed in a desperate finish. Mastery stayed on at one pace for third.

Eddie Ahern was soon sending out distress signals on Father Time, who trailed home well beaten.

It was O'Brien's first Breeders' Cup winner since High Chaparral earned top honours in the Breeders' Cup Turf in 2003. In the interim, he has had seven seconds.

He said: "That was brilliant. We're delighted. Johnny gave him a wonderful ride. Johnny said that he was just going to take his time because that's the way he likes to be ridden. That's what he did. It was just a marvellous ride."

Murtagh meanwhile said: "It was his first time over the course so I let him just go along without any hurry. I wanted to stay out of trouble. I asked him at the three-eighths pole and he responded beautifully. He got the win right on the wire so it worked out just right."

John Magnier, part of the Ballydoyle triumvirate, said: "Johnny called the race correctly. He said he would be taking his time and once Johnny got in there with a chance, Johnny always has a chance.

"We'd forgotten our way to the winner's circle but now we've found our way here, let's hope there are a few more."

Dettori said of Mastery: "He danced one too many times this year. Everything is all right, the whole race went perfect, but the horse just had a long season."

Trainer Saeed bin Suroor added: "He's run OK but I'm disappointed with the result.

"Coming off the bend I thought he was going to win, but he's been beaten by a better horse on the day and we have plenty with good chance over the remainder of the meeting."

Homeister jnr said of the runner-up: "He's just a fantastic horse and has run his best ever race.

"We got to the quarter pole and I asked him and he's given me everything.

"He could see the horse on his outside (Mastery) but not the one on his inside (Man Of Iron) and he's just got pipped.

"I thought we had won, but we've just been beaten by a bob of heads."