The phrase "a defining victory" is correct and usable in written English.
It can be used to describe a victory that significantly shapes or influences a situation, outcome, or perception.
Example: "The team's performance in the championship game was a defining victory that solidified their reputation in the league."
Alternatives: "a pivotal win" or "a landmark victory".
For Orobets and her fellow-politicians, the challenge is appealing to a generation for which the Maidan was a defining victory.
In Pakistan, Kayani faced rumbles of insurrection for letting Americans violate Pakistani sovereignty; a defining victory for President Obama was a humiliation for Kayani and Pasha.
She has crawled into the top 10 and is prowling for a defining victory to vault her into the discussion of major-tournament favorites.
Conte had been plotting and when he emerged at the Stade de France he needed to have the blueprint for a defining victory.
It also underscores the importance of a trial in which Mr. Tourre is fighting a possible ban from the securities industry, and the S.E.C. is seeking a defining victory in its uneven campaign to punish those at the center of the crisis.
In Tuesday's other Grade One race, Mount Benbulben finally lived up to his tall reputation with a defining victory over fences in the Champion Novice Chase under Danny Mullins.
He can box, but he chose in a defining 2012 victory over former welterweight champion Andre Berto in Ontario and last year's decision over Japan's Yoshihiro Kamegai in Carson to go toe-to-toe.
Defining victory as expelling the Iraqis from Kuwait, they quit while they were ahead.
But that defining victory can still instruct us, among other things, about the link between marriage and liberty.
The defining victory of his career, against Wladimir Klitschko, should have been feted for years, instead his boxing triumph was obscured by the force of a feckless tongue.
Nowhere was this mutualism more starkly cast than in Flint, where General Motors was founded, and the U.A.W. gained its defining victory.
