The six-year-old was partnered by Danny Tudhope in the American feature, settling well off the pace and still having plenty of ground to make up on the leaders at the top of the straight.
Heart To Heart, who had raced prominently throughout, looked a likely winner as he fended off Miss Temple City but Suedois was flying down the middle of the track, getting up to win by half a length in the final strides with Ballagh Rocks third.
Suedois was tackling a mile for just the third time in his career and O'Meara, who also sent out Mondialiste to finish fifth, believes the longer trip suits his charge.
He said: "We've targeted horses in this country before quite successfully and the money was very big.
"We wanted to keep him at a mile. We contested him in five or six Group Ones last year and he was hitting the woodwork in them all.
"He was placing in most of them. It's something I always wanted to do, to step him up to a mile. And since he's come up to a mile now, he's won two out of two.
"Maybe I was running him over the wrong trip all along."
Suedois' victory earns him an automatic place in the Breeders' Cup Mile as part of the 'win and you're in' series, but O'Meara is yet to commit to that race on November 4.
He added: "We'll have to chat with the owners. We'll just have to see."