Bancroft made 100 as WA posted 5-290 at Melbourne's Junction Oval.
The ex-Test batsman was dismissed by Victoria's latest Shield debutant - a 31-year-old Sri Lankan - after featuring in a 146-run stand with opening partner Sam Whiteman (82 from 142 balls).
Whiteman was dismissed in the 46th over - the lefthander nicked down the leg-side from the bowling of Will Sutherland (1-42).
Bancroft struck nine fours in his 20th first-class ton but was dismissed soon after reaching the milestone, stumped.
The 29-year-old, who last played Test cricket in August 2019, was the initial first-class wicket of Victoria's Sri Lankan-born legspinner Ruwantha Kellapotha, who finished with 1-78 from 21 overs.
West Australian Teague Wyllie (49) failed to cash in on a bright start when was caught and bowled by Matt Short (1-13) while Hilton Cartwright was unbeaten on 39.
Josh Phillipe (five) was also dismissed caught and bowled, by Todd Murphy (1-70), as Victoria rallied late in the day, taking 4-64.
The West Australians included speedster Jhye Richardson after he missed their Shield-opening eight-wicket win against NSW because of a hamstring niggle.
Richardson has not played a red-ball game since Adelaide's Ashes Test in late December.
The paceman, who has set his sights on Australia's Test series against the West Indies and South Africa this summer, returns against a Victorian side held to a draw by South Australia in their Shield opener.
12°C