Marsh's 27th first-class ton piloted the hosts to 4-256 at stumps, in reply to Victoria's 341 at the WACA Ground.

The 36-year-old finished the day's play unbeaten on 101, with Marcus Stoinis (56) and Hilton Cartwright (42) also chipping in.

WA reached 2-137 at tea before Marsh, captaining the side in the absence of injured younger brother Mitch, reached his century off 184 balls.

The elder Marsh was dropped twice - first by Chris Tremain at gully on two off the bowling of Scott Boland then by Sam Harper on 51, with the Victorian wicketkeeper unable to hold on to a reasonably difficult chance while diving to his left.

"It was very satisfying," Marsh said.

"I got a bit of luck along the way but it was nice to walk off at the end there and put the team in a reasonably good position if we come out tomorrow morning and play well.

"Obviously they'll come pretty hard at us first thing in the morning so we're going to have to work really hard through the new ball."