Magic Hurricane ($3.10 fav) was a dominant victor in the $750,000 staying contest, bursting through the ruck inside the final 250-metres to career away under the urgings of James McDonald to record a two length-win.
Chris Waller's veteran stayer Beaten Up ($10) finished second with another O'Shea runner, Havana Cooler ($10) third, a further long head away.
As Godolphin's retained jockey, McDonald also made it five winners for the day.
O'Shea and McDonald combined earlier to win the Listed Gimcrack Stakes with Calliope, the Listed Dulcify Quality with Ambience, the Group II Roman Consul with Exosphere and the Group III Craven Plate with Complacent.
"I'm humbled by the opportunity,” O'Shea said. "I'm always grateful for the performance of my team.
"We knew we had the horses right. Then it was just a matter of Mac putting them in the right spot and things working out for us.”
O'Shea already had the Group I Caulfield Cup eyed-off for his duo that split the line in the Craven Plate (2000m) - Complacent and Hauaki - and can now add Magic Hurricane to the list of entrants carrying the Godolphin blue - if he gets a start.
"Hopefully Magic has made his way into the race,” O'Shea said. "He's just coming right.
"He'll have to get a penalty and whether or not that's enough to get him into the race, but if they're happy enough to have him we're happy enough to run him.”
McDonald's riding performance on Sydney's biggest spring racing day of the season was outstanding.
"Yeah it's amazing,” McDonald said. "It's actually fantastic to be a part of Godolphin's team.
"I play a very small role but I'm just privileged that I'm riding for one of greatest empires in the world.”
Magic Hurricane was purchased to race in Australia after having 10 starts in the UK for two wins.
The six-year-old gelding by Hurricane Run has had six runs in Australia for three wins and the Metropolitan victory was his first Group I success.
Sportsbet have tightened him into $21 for the Group I Caulfield Cup (2400m) to be run on October 17.