By Steve Ginsburg

BALTIMORE (Reuters) - Unbeaten and still untested, Big Brown followed up his convincing Kentucky Derby victory by winning the Preakness Stakes in dominant fashion at Pimlico Race Course on Saturday.

Big Brown, the overwhelming favorite ridden by Kent Desormeaux, grabbed the lead at the top of the stretch and easily drew away from the field for his fifth career triumph.

"Unlike in the Kentucky Derby where I had to start knuckling on him to get him to go get the leaders, today I was slowing him down not to pass the leaders," said Desormeaux.

"It was really a dramatic change from two weeks ago in the Kentucky Derby."

The Kentucky-bred son of Boundary will run in the Belmont Stakes on June 7 in New York with hopes of becoming the 12th Triple Crown winner and first since Affirmed in 1978.

Derby trial winner Macho Again finished second in the 12-horse race, while Tesio Stakes champion Icabad Crane took third.

The winning time of 1:54.80 was off the Preakness record of 1:53.40 set in 1985 by Tank's Prospect and equaled by Louis Quatorze in 1996.

Big Brown, whose average margin of victory is nearly eight lengths, broke cleanly from the sixth post before moving to the rail to stalk early leaders Gayego and Riley Tucker.

Desormeaux moved Big Brown to the outside at the three-eighths pole (600m from the finish) and grabbed the lead from Racecar Rhapsody at the top of the stretch.

The bay colt, who won the Kentucky Derby by 4-¾ lengths, cruised to the finish line for a 5-1/4-length victory.

Big Brown returned $2.40, $2.60 and $2.40 for a $2 ticket. Macho Again paid $17.20 and $10.40, while Icabad Crane returned $5.60.

(Writing by Steve Ginsburg; Editing by Justin Palmer and Greg Stutchbury)