#1 Kevin Owens defeats John Cena in his first main roster match

Kevin Owens' main roster career began with a bang as he was immediately programmed against WWE's biggest star, John Cena, making his debut on the May 18, 2015 episode of Raw, where the then-NXT Champion answered Cena's United States Championship open challenge.
Owens didn't contest a match with Cena, he attacked him instead, brutalizing him and then stamping on the US title to mock and disrespect the title and Champion.
The pair clashed in a non-title affair at Elimination Chamber on May 31, 2015 where he defeated Cena clean by pinfall (one of a select few to so since 2005) in one of the most shocking results of the decade.
A 20-minute stunner, the pair constructed one of the best matches of 2015 as they fought back and forth before Owens executed a pop-up power-bomb for the win.
Owens had arrived with quite possibly the best debut match possible.