The pair stalked the red-hot favourite Zed Em and his stablemate Pentelligentsia before getting the better of rivals deep into the straight to win by 3.5 lengths.
It completed an amazing comeback for Spying On You, the 2017 winner almost retired due to injury and a jump-less 2020 season.
"It's pretty amazing," Young said on Racing.com post-race.
"I couldn't be prouder of him. What a great performance."
It was an Oakbank full of comebacks. Street Life upstaged his rivals in the Hills Railway Stakes to give rider Emily Finnegan her first feature in combination with Murray Bridge trainer Karen Byrnes.
"I had the whole pressure of Oakbank on me today," Finnegan said post-race.
"You don't realise how much you miss it until you get that feeling again."
Travis Doudle landed a Saturday double, highlighted by the return to winning form of Analytica, who claimed the Onkaparinga Cup, while Casino Seventeen was impressive early in the day.
At Clare on Easter Saturday Kym Healy took training honours with a double, while Cuban Toonite claimed Sunday's Penola Cup with Ben Price in the saddle, one of three winners for Sue and Jason Jaensch.
And Gawler horseman Gary Searle walked away from Easter Monday with a double on his home track when Secret War and Winter Harbour were successful.
But Monday's most impressive win by a South Australian came at Sandown, where Will Clarken's Beau Rossa made a mess of rivals to score by seven lengths with Jamie Kah in the saddle.
Kah and fellow local Will Price shared riding honours with a double each.