A perfect ride by top Melbourne jockey Craig Williams helped Southern Speed to a 1-length victory over one of her "big number" rivals, Green Moon, with Tullamore in third place.
Green Moon is owned by Lloyd Williams, the man who built Melbourne's Crown Casino and one who has rolled the dice relentlessly in a bid to find big-race winners around the world.
The entire, who began his racing life in England where he won three races, is one of 10 Northern Hemisphere horses who joined Williams' team late last year.
Third placegetter Tullamore is trained by Gai Waterhouse, who turns over more than 100 horses each season in a bid to find those who can win the big-money races.
Further back in the field were such horses as Mighty High, trained in Hong Kong by expatriate Australian John Moore, the son of legendary jockey George Moore.
The most successful trainer ever in Hong Kong, Moore's horses have won and raced around the world.
Also back in the pack were the international raiders Manighar and Drunken Sailor from the stable of Luca Cumani, one of England's most successful trainers.
Cups King Bart Cummings saddled Precedence, who ran 10th, and the German raider Lucas Cranach, prepared by the powerful Freedman stable, was fifth.
The favourite December Draw, another imported runner, finished last after racing near the rear all the way.
As they all toiled and failed, veteran South Australian Macdonald had only a fleeting concern that things were going too well for his mare.
"At the 600m I was worried she mightn't get off the fence," he said.
That worry may have been only a small one, but Southern Speed's win was accompanied by a large regret that Macdonald's regular jockey Clare Lindop hadn't been in the saddle.
"Clare did all the early work with her, it's not good," he said.
Macdonald didn't say so, but he made it clear the choice of jockey was not his.
Meanwhile, Williams is only one win away from becoming the eighth rider to win the big four majors after the emphatic victory.
The Melbourne Cup is the only one of the quartet of features missing from the jockey's cabinet after his victories on Miss Finland and Fields Of Omagh in the 2006 Golden Slipper Stakes and Cox Plate respectively and Saturday's Caulfield Cup.
A four-time Melbourne premier rider, Williams said Southern Speed's win was a career highlight and in many ways a day of redemption for his defeat on Leica Falcon in the 2005 Cup.
With average luck Leica Falcon may well have won that year and on Saturday Williams finally got the breaks.
"Leica Falcon left a bad taste in my mouth but that is history now," Williams said.
Williams picked up the ride on Southern Speed after stable rider Lindop was put off the mare and Dan Nikolic couldn't ride her in the Turnbull Stakes at Flemington.
Williams finished fourth on her in the 2000m Turnbull and the natural lightweight was always going to ride her in the Caulfield Cup at 52.5kg providing she got a start.
She was only just inside the top 40 in qualifying order and lined up on Saturday with number 18 saddlecloth to the relief of Williams and connections.
Southern Speed threw out her challenge at the top of the straight and charged away to win by 1 lengths from Green Moon.
The only mare in the Cup, Southern Speed, had gate three and Williams had her fourth on the rails all the way.
"She gave me a really good run throughout from the draw and made it easy for me," Williams said.
"Niwot gave me a nice run out [of the straight] then when Green Moon went forward I knew he wouldn't give up.
"We saw how tough he was when he won the Newcastle Cup and I thought we have just got to get out off his back.
"We didn't over-rush her. I just built her up and she went through her gears.
"When I pressed the button we had to fight for 150m with Green Moon then when she got on terms I got really serious on her and asked her for bit more and she really ran away with it.
"She was very commanding at the end. Very dominant."
Williams acknowledged Lindop, who galloped Southern Speed during the week despite having to watch the race from the stands.
"She put the finishing touches on her for me and I was just lucky," Williams said.
"To win this race is fantastic. It was one of the four majors and I have been lucky enough to win three."
The challenge now for Williams is to try to find a mount for the Melbourne Cup as Southern Speed wasn't even nominated for the race.
Trainer Peter Snowden has declared champion 3-year-old Sepoy "in the zone" for the Coolmore Stud Stakes at Flemington on Victoria Derby Day after a dominant win against older horses in the Caulfield Sprint.
Sepoy made it nine wins from 10 starts in the 1100m group two feature and controlled the race from start to finish, with jockey Kerrin McEvoy likening the effort to a barrier trial for the colt.
Snowden was excited by the winning time of 1:03.11 but Sepoy could have gone faster as McEvoy didn't push the $1.22 favourite out to the line to win by 1 lengths from Peter Moody-trained stablemates Curtana ($21) and Mid Summer Music ($12).
"That is an absolutely outstanding time," Snowden said.
"He's a very, very special horse."
"What he's done hasn't been done by very many horses, only champion horses and he's one of them.
"I am pretty hard who I claim is special and this fellow is still learning his trade."
Snowden acknowledged there was a lot of hype about a clash with unbeaten champion Black Caviar but he said Sepoy needed more time to reach her class.
"To me he is 12 months away from looking at a race like that.
"He is getting better. He's learning more and more about what's he's got to do." Snowden confirmed the Coolmore Stud Stakes (1200m) as Sepoy's next assignment.
Black Caviar will try for her 15th win a week later in the Patinack Farm Classic (1200m) at Flemington.
Sepoy is the third 3-year-old to win the Caulfield Sprint and carried 55.5kg, 3kg more than Campaign King in 1985.
Jet Spur won with 52kg in 2005.
Snowden said Sepoy had peaked this campaign. "He is in the zone now and it is my job to keep him there for two more weeks."
Sepoy coasted to the lead halfway up the straight and while McEvoy could hear Curtana and Mid Summer Music closing he always had them covered.
- AAP
