Plays that shaped Steelers' season: No. 7

Here is the next installment of plays that shaped the Pittsburgh Steelers' season.

No. 7

The play: Minnesota Vikings wide receiver Greg Jennings catches a 70-yard touchdown pass from quarterback Matt Cassel in a Sept. 29 game in London.

The situation: The Steelers, trailing 3-0 midway through the first quarter, allowed Jennings to turn what should have been less than a 10-yard catch into one of the biggest plays of the season against the Steelers' defense. Cortez Allen and William Gay each whiffed badly on tackle attempts and Jennings outran the rest of the Steelers' defense after breaking into the open field. Jennings, taking advantage of soft coverage by Allen, had run a short route that should have given the Vikings a first down but certainly not a touchdown.

Why it mattered: That touchdown gave the Vikings a 10-0 lead and set the tone for the kind of shoddy performance usually not associated with Steelers defenses. For a team that came up a win short of making the playoffs, this loss hurt even more since it came against one of the more underwhelming teams on the Steelers' schedule. Jennings' catch and run also revealed cracks in a defense that had played well in the first three games of the season, even in a 40-23 loss to the Chicago Bears the previous week. The Bears managed only 258 yards of total offense and scored two defensive touchdowns. The collapse of the Steelers' defense in London portended inexplicable breakdowns that doomed Pittsburgh to a second consecutive non-winning season.