South Australia 7 for 438 dec (Drew 208* and 6 for 191 dec (McSweeney 104*) beat Western Australia 162 and 303 (Bancroft 80, Cartwright 50, McAndrew 4-73) by 164 runs
Sheffield Shield strugglers South Australia secured a memorable 164-run win over runaway leaders Western Australia at Adelaide Oval with the result lifting them into third on the table.
South Australia have finished bottom in each of the past five seasons since making the Shield final in 2017 and were up against a Western Australia side boasting four wins from six outings, and bolstered by returning star batters Marcus Stoinis and Shaun Marsh.
Western Australia began the day at 2 for 139 in pursuit of a massive 468-run winning target, but were eventually bowled out midway through the middle session for 303.
Bancroft was out for 80 in the second over of the day, having added only one to his overnight tally.
From there WA failed to build long partnerships despite runs for Hilton Cartwright, Aaron Hardie and Josh Inglis.
Having accumulated just five wins in the past five seasons, South Australia have now posted successive triumphs following on from a victory over Tasmania before the mid-summer break.
"It's massive for us," said Agar in reference to winning back-to-back matches. "We know that we have been in a bit of a struggle in the past couple of years, but we knew we had talent and that it would take time.
"To start seeing us get into winning positions, and then actually winning games of cricket is awesome for us and gives us a lot of confidence."
"It is a great sign for us that we are having multiple contributors," Agar said. "On that surface it was just about being patient [with the ball], not going searching too much and that is very pleasing."
Western Australia are still two wins clear at the top with three rounds remaining as they seek to again earn hosting rights for the Shield final.
'Massive for us' - South Australia topple Shield leaders WA to hint at revival
Nathan McAndrew led the way in the second innings with key wickets
Bancroft holds up South Australia's push for notable victory
Western Australia still need 329 on the final day after Nathan McSweeney's second-innings hundred
Agar and McAndrew fire to skittle leaders Western Australia
Daniel Drew made an unbeaten double century in the home side's first innings
West Aust Innings