KANSAS CITY, MO – In what looked like a day of disappointment from early on in the first quarter, what fans remained by game's end at Arrowhead Stadium saw a thrilling finish in the season opener against AFC West foe San Diego Chargers.

On the 15th anniversary of the terror attacks of Sept. 11, 2001, the red, white and blue was in full force Sunday afternoon. But for the first three quarters, the Chiefs (both offense and defense) were nowhere to be found.

The Chiefs offense, led by Alex Smith, was on task in their first drive of the game, which resulted in a Cairo Santos 47-yard field goal try. Santos converted, and the Chiefs were in the lead 3-0.

Phillip Rivers took over on offense for San Diego and led the Chargers 75 yards down the field for a touchdown in six plays. The drive was highlighted by two completions of 47 yards for Rivers. Melvin Gordon eventually punched the ball in the end zone from one yard out.

The Chiefs couldn’t muster a point and had to punt over the course of their next five drives after the field goal. San Diego, on the other hand, built a 21-3 lead by halftime. Chargers wide receiver Keenan Allen was having a day for himself with six receptions for 63 yards, but Allen suffered what looked to be a serious leg injury with about one minute left in the first half.

With 6:06 left in the third quarter, Josh Lambo converted on a 29-yard field goal and put San Diego up 24-3. The Chiefs countered four minutes later, when Smith threw a nine-yard pass to rookie Tyreek Hill for a touchdown, bringing the score to 24-10.

At the opening of the final quarter, Lambo converted once again on a 28-yard field goal. Down 17, the Chiefs were essentially out of the game. But the defense made some key stands, and Smith found Jeremy Maclin for a 19-yard touchdown with 9:18 remaining in the game.

After forcing a San Diego punt, Santos made his second field goal of the day from 33 yards out. The Chiefs were trailing 27-20. The Kansas City defense once again forced a San Diego punt at the two-minute mark in the fourth quarter. Down seven, the Chiefs somehow had a chance to tie the game.

A 17-yard San Diego punt took a generous bounce, which resulted in the Chiefs starting their drive in San Diego territory at the 32-yard line. Smith completed a missile to Maclin for a first down at the 11-yard line. Maclin absorbed a massive hit, and roughing the passer was called, which resulted in a penalty and put the Chiefs five yards from a tie game.

With 1:03 left, the Chiefs completed a miraculous comeback. Spencer Ware punched the ball in from five yards out. Down 21 in the third quarter, the Chiefs somehow had tied the game. Overtime ensued.

The Chiefs had scored 17 unanswered points in the final 9:18 of the game. The Chiefs won the toss in overtime and received first possession. After being evaluated for a concussion as a result of the hit on the game-tying drive, Maclin found his way back onto the field for the Chiefs’ first possession of overtime.

After getting to the two-yard line, the Chiefs took a timeout on third and goal with 9:59 remaining. Smith came out of the timeout and took the ball two yards into the end zone.

Somehow, some way, the Chiefs finished a miraculous comeback and beat the Chargers 33-27.

STAT OF THE GAME

The Chiefs’ comeback victory from 21 points down was the largest deficit that a Cheifs has overcome in the franchise’s history. At halftime, according to ESPN, San Diego had a 93.7 percent chance of winning the game.

LEADING PLAYER

Obviously the Chiefs would not have been able to come back without Smith’s in the second half. But Ware was Smith’s best option out of the backfield. While he rushed for 70 yards and scored a touchdown, Ware also caught seven passes for 129 yards.

"He [Spencer Ware] brings a lot of energy, and he's an emotional player," Reid said after the comeback win. "He has a knack for making plays when you need them. He did that today."

UNSUNG HERO

The Chiefs' defense made the historic comeback possible. The unit held San Diego to just three second-half points. While the injury to Allen at wide receiver no doubt hurt the passing game for the Chargers, the Chiefs were able to stifle anything that San Diego got going.

NOTEWORTHY

Smith led the Chiefs to touchdowns in his final three drives of Sunday’s game, including overtime.

WHAT’S NEXT

The Chiefs travel to Houston next weekend to take on the Texans in a rematch of last season’s Kansas City playoff victory.