Stafford tried to hit Johnson in triple-coverage, but Pittsburgh's Will Allen picked it off and returned it to the Detroit 34. Five plays later, Roethlisberger floated the ball to a wide-open Jerricho Cotchery for a 20-yard touchdown and the comeback was complete.
Detroit's collapse was hard to imagine during an explosive first half as Johnson and Stafford did whatever they wanted.
Steelers cornerback Ike Taylor said last week he couldn't wait for the chance to go "mano-a-mano" with the NFL's best receiver. Like nearly every player who has lined up across the line of scrimmage from Johnson over past three years, the matchup looked like a mismatch.
At least, for a while.
Taylor landed a blow early, knocking down the first pass Stafford threw Johnson's way. The 11-year veteran and his befuddled teammates couldn't get a hand on the second. Or the third. Or pretty much anything else the Lions and their superstar wide receiver felt like doing.
The Lions spotted the Steelers a 14-0 first-quarter lead as Roethlisberger hit Brown for touchdowns of 34 and 47 yards, an avalanche of points for Pittsburgh's sputtering offense but barely a blip for one of the league's most explosive offenses.
Detroit needed to hold the ball for 6:37 to set a franchise record for points in a quarter. Johnson, as he tends to be, was right in the middle of it. He started the onslaught with an impossibly easy 79-yard touchdown, taking a heave from Stafford at the Pittsburgh 40 and then practically jogging into the end zone to make it 14-10.
Johnson was at it again the next time the Lions had the ball, beating the coverage to the inside for a 19-yard score to tie the game at 17.
Taylor became so frustrated that at one point he was flagged for holding and pass interference on Johnson on consecutive plays late in the first half, though the penalties served their purpose. Rather than get a last-second touchdown to go up by 10 at the break, the Lions were forced to kick a field goal and settle for a 27-20 lead.
All of that momentum, however, vanished as quickly as it appeared.
Rather than adding to a resume that includes a road win at Chicago and a thrilling comeback against Dallas, the Lions continued a flabbergasting pattern of erratic play while the Steelers stoked - for another week at least - whatever flicking postseason hopes they have of getting back to .500 and perhaps beyond.