Season-shaping play: William Gay's first pick-six

This is the eighth in a series that looks at 17 plays that shaped the Pittsburgh Steelers' season -- one from every game.

For this series we will go in chronological order.

No. 1: Le'Veon Bell's 38-yard touchdown run in a 30-27 win against the Cleveland Browns.

No, 2: Wide receiver Justin Brown's lost fumble after a 6-yard reception in a 26-6 loss to the Baltimore Ravens.

No. 3: Outside linebacker Jarvis Jones' sack of quarterback Cam Newton for an 8-yard loss in a 37-19 win against the Carolina Panthers.

No. 4: Wide receiver Antonio Brown’s drop of a sure touchdown pass in a 27-24 loss to the Tampa Bay Buccaneers

No. 5: Cornerback Brice McCain's 21-yard interception return for a touchdown in a 17-9 win against the Jacksonville Jaguars.

No. 6: Cornerback Cortez Allen getting beat for a 51-yard touchdown catch by Cleveland Browns tight end Jordan Cameron.

No. 7: Bell's 43-yard reception in a 30-23 win against the Houston Texans.

No. 8: Cornerback William Gay returns an interception 33 yards for a touchdown against the Indianapolis Colts.

The setting: Two of quarterback Ben Roethlisberger's six touchdown passes in a shootout at Heinz Field gave the Steelers a 14-3 lead early in the second quarter. The Steelers built on that lead after Colts quarterback Andrew Luck tried to answer.

The play: Colts wide receiver Hakeem Nicks ran a hitch route and Gay jumped it. Luck threw one of his worst passes of the season, and Gay caught it in stride and scored easily to give the Steelers a commanding 21-3 lead.

What it meant for the bigger picture: Luck put up big numbers the game but could never bring the Colts back from the early 18-point deficit. The Steelers went on to win 51-34, giving them the signature victory that had eluded them through most of the first half of the season. Gay, meanwhile, returned all three of his interceptions in 2014 for touchdowns, setting a Steelers record for most pick-sixes in a season. The Steelers were 3-0 in games in which Gay returned an interception for a touchdown.