Unwanted by his old state and signed almost as afterthought by his new one, Nic Maddinson has scored a stunning unbeaten century on JLT Sheffield Shield debut for Victoria.

The home side are in charge at 3-311 against Western Australia at stumps on day one at the MCG thanks largely to Maddinson's superb innings in his first Shield appearance since his acrimonious split with NSW.

The three-Test batsman blasted two sixes and 21 fours in his 159 runs from 282 balls to make the most of the opportunity that only came about because Peter Handscomb, Marcus Harris and Aaron Finch are wearing the baggy green in Adelaide.

Cameron White will resume with Maddinson on Saturday, his 65 runs coming from 112 balls and including 10 fours.

Maddinson survived a scare on 92 but his reprieve came at the expense of Glenn Maxwell.

In a bizarre turn of events, WA seamer Matthew Kelly dropped a sharp return chance off Maddinson but the ball deflected off his hand back onto the stumps with non-striker Maxwell out of his crease.

Maxwell had batted impressively coming in up the order at No.4 but had to depart on 57 from 91 deliveries.

In the morning session, Victoria raced to 0-62 after stand-in skipper Travis Dean won his first Shield toss and elected to bat.

But WA applied the brakes when Dean (16) and Will Pucovski (1) departed.

Dean is filling in for regular captain Handscomb, preferred in the Test XI at the expense of Mitch Marsh, who returned to lead WA.

Marsh was expensive in his opening spell, conceding 25 runs from three overs, but tightened up to have the figures of 0-58 from 14 overs.

Allrounder Marcus Stoinis was the pick of the bowlers with 1-30 from 16 overs with six maidens.

The visitors are without spinner Ashton Agar, who has been rested.

The Vics are just over eight points clear at the top of the table heading into round six, with WA third.

Victoria XI: Travis Dean (c), Nic Maddinson, Will Pucovski, Glenn Maxwell, Cameron White, Matt Short, Sam Harper, James Pattinson, Scott Boland, Jon Holland, Chris Tremain.

Western Australia XI: Mitchell Marsh (c), Jonathan Wells, D'Arcy Short, Hilton Cartwright, Marcus Stoinis, William Bosisto, Ashton Turner, Josh Inglis (wk), Jhye Richardson, Matthew Kelly, David Moody