"My bloke is a terrific stayer and the further he goes the better. He can be a little bit volatile, but he relaxes in his races," Baker said.
"He'll be going to Randwick for the ATC Derby. He's right up there with the Derby winners I've had in Australia."
He won the Group 1 feature with Nom du Jeu in 2008 and two years ago with It's A Dundeel.
Baker is in his third season with Andrew Forsman and they have proved a formidable combination sitting atop of the premiership with 71 winners. Baker's personal best is 73 set in 2008-09.
Mongolian Khan settled just off the pace set up by the filly Vavasour before Bosson urged him into contention near the turn.
They were headed soon after by Volkstok'n'barrell, but the superior stayer won the war with Mongolian Khan rallying strongly for a length decision.
"It's a huge relief really," Bosson said. "To my horse's credit, he pinned his ears back and fought right to the line. It's a race I've been trying to win for so long and it's quite humbling."
— NZ Racing Desk