A.J. Styles retains WWE championship at No Mercy

It was an unconventional decision to kick off Sunday's WWE No Mercy pay-per-view with the main event, but the incredibly high level of SmackDown Live shows the past month helped set the stage for a thriller -- and the tone for the night.

There are any number of reasons the WWE chose to open with the triple threat WWE world championship match, which was won by defending champion A.J. Styles via pinfall at 21 minutes, 15 seconds over John Cena and Dean Ambrose at Golden 1 Center in Sacramento, California.

Sure, it's a good way to draw early viewers on a night with plenty of competition, including a presidential debate and a Sunday Night Football game. But there's also the strength of the rest of the card and the ability to close strong with a match such as the career vs. title Intercontinental championship match on top of everything else.

The triple threat match had everything fans might have wanted: crazy in-ring action, points at which you believed each of the three competitors had grabbed the momentum and great storytelling inside the ring. Styles managed to pick up the victory despite tapping out mid-match, and he did it once again in a heel manner by hitting Cena with a chair and picking up the pinfall victory.

Styles, Cena and Ambrose took the unusual approach of going back and forth among the three of them over the first few minutes of the match, with the first signs of separation coming when the trio executed a double German suplex. The maneuver drew the first "Mama Mia" of the evening from commentator Mauro Ranallo, as Cena lifted both Styles and Ambrose into the air.

There was a moment in which Styles showed a flash from his TNA past by hitting a springboard moonsault from the middle rope and catching Ambrose in an inverted DDT position. He completed the crazy combination by simultaneously hitting a neckbreaker on Cena. A quick two-count was soon followed by Cena's getting in some unique offense by hitting a Code Red on Styles for another two count.

One of the biggest complaints (and one true drawback to matches involving different combinations of this trio) -- too many finishers without an ending to the match -- was handled well in this triple threat showdown. We were well into the match before the first finishers, a pair of Attitude Adjustments from Cena, were hit. Styles rolled out of the ring to save himself, and Ambrose kicked out only at the very last moment.

There was a Styles springboard 450 and impressively athletic moves from both Cena and Ambrose, but each and every time a finisher came into play, the third man was able to break up the pinfall or submission before one of his opponents could pick up the victory

It was an interesting twist to have both Cena and Ambrose put on different parts of a submission and have Styles tap out, if only because WWE fans have far too many memories of screwy finishes and titles being vacated under such circumstances. Referee Mike Chioda's decision to have the match restarted because neither Cena nor Ambrose was the clear victor was followed by a collective sigh of relief from an audience that worried there would be some kind of incomplete finish to a match of this caliber.

Allowing Styles to get the pass in this scenario -- and ultimately, the victory, despite it -- was a wonderful touch, and having him do so by pulling out a chair and nailing Cena twice for the victory worked well. You don't often see a three-way feud carry on beyond a single pay-per-view, but in this case, it seems this trio has more of a story to tell.

For full match recaps and ratings from WWE No Mercy, click here.