“It was my fault. It was pathetic.” Denver Broncos safety Rahim Moore, on the 70-yard touchdown pass from Baltimore’s Joe Flacco to Jacoby Jones, which tied the score at 35-35 with 31 seconds remaining in the fourth quarter of an A.F.C. divisional playoff game at Denver.

How bleak was it for the Ravens? They trailed, 35-28, and they had no timeouts remaining. One minute nine seconds remained when the Ravens got the ball at their 23. Any passing play or running play that ended in the field of play would have resulted in a large chunk of time being run off the clock. At one point in the final two minutes, according to the AdvancedNFLstats.com probability graph for the game, Baltimore had only a one percent chance of winning the game.

After an incompletion on first down, Flacco slid to the ground after a 7-yard gain, setting up a third-and-3 that won’t soon be forgotten.

Here is a second-by-second account of the play:

:57 – Flacco scrambled to his feet after his second-down run and immediately held two fingers in the air 
The Ravens could not afford to spike the ball to stop the clock because a wasted down would leave them with only one play to extend the game.

:53 – With the clock ticking, a nervous-looking John Harbaugh watched as Flacco waited for his teammates to get back to the line.

:42 – Flacco took the snap from the shotgun formation, with Ray Rice lined up next to him 
To Flacco’s right, Jacoby Jones was the outside receiver lined up across from Broncos cornerback Tony Carter. The Ravens’ Dennis Pitta was on the inside covered by Mike Adams. On Flacco’s left was Torrey Smith, covered by Denver’s Champ Bailey, and Anquan Boldin.
The Broncos’ Moore, who had the deep outside coverage on the right side of the field, was lined up on the Baltimore 45, ominously only 15 yards off the line of scrimmage. Did the Broncos defensive coordinator Jack Del Rio forget that Flacco had burned them for two long TD passes earlier in the game? Carter was lined up at the Baltimore 35.

:40 – Flacco, quickly under pressure in the pocket even from a three-man rush, scanned the field
Moore, backpedalling, turned toward the middle of the field at the Denver 45 as he appeared to react to a move by Pitta. Jones, running down the right sideline, was at the Denver 48 three yards ahead of Carter.

:38 – Flacco released the pass from the Baltimore 25
Moore, incredibly, was still backpedalling near the Denver 40-yard line. Jones was running full speed, clear of Carter, at the Denver 42.

:34 – Flacco’s pass was caught by Jones at the 20-yard line 
How many breakdowns were there on this play? Consider: Had Moore been late to cover Jones but had still made the tackle, the Broncos would still have been in good shape. Flacco and the Ravens linemen were still more than 50 yards up the field. It had taken 18 seconds from the time Flacco was tackled on a 7-yard run on the previous play to when he was able to take the snap on third down. It most likely would have taken at least 25-30 seconds to take the next snap, which would have left the Ravens with one or possibly two more plays.

:31 Jones waltzed into the end zone

For historical reference, the Hail Mary pass from Roger Staubach to Drew Pearson in Dallas’s 17-14 playoff victory over Minnesota in 1975 covered only 50 yards on a play that started with 32 seconds left. The Cowboys had faced a fourth down from their 25 with 44 seconds remaining.

Flacco’s 70-yarder to Jones with 31 seconds remaining will carve its own place in N.F.L. playoff lore.