Arrogate has proved his class and courage to win the Dubai World Cup and become the world's most financially successful racehorse.

The Bob Baffert-trained four-year-old was sent off at Meydan at the long odds-on favourite after wins in the Breeders' Cup Classic and Pegasus World Cup Invitational, but appeared to have lost all chance of victory following a slow start.

But jockey Mike Smith showed all his experience and did not panic, weaving in and out of the field to gradually made up ground and scoop the $US6million prize and take Arrogate's earnings to a record $US17million.

Rounding the turn for home he was making up many lengths, but Gun Runner appeared to have stolen a march.

But Arrogate found another gear and he bounded clear to give Baffert a third win in the race.

"When he missed the break, I gave him no chance at all," Baffert said.

"I was so mad at myself thinking I shouldn't have brought him - that's the greatest horse I've ever seen run, it's unbelievable, I can't believe he won. That is a great horse.

"Mike did a great job, he didn't panic.

"When he turned for home I said 'If he wins he's the greatest since Secretariat'."