Coming off of a bye week, the Steelers flew to INVESCO Field at Mile High for a Sunday night intraconference clash with the Denver Broncos.  In the first quarter, Pittsburgh struck first with QB Ben Roethlisberger completing a 1-yard TD pass to TE Heath Miller.  Afterwards, the Broncos responded with QB Jay Cutler completing a 15-yard TD pass to WR Brandon Stokley.  In the second quarter, the Steelers struggled as Cutler completed a 1-yard TD pass to FB Cecil Sapp, along with DE Tim Crowder returning a fumble 50&#160;yards for a touchdown. In the third quarter, Pittsburgh tried to recover with Roethlisberger completing a 13-yard TD pass to WR Santonio Holmes, but the Broncos answered with Cutler completing a 1-yard TD pass to TE Tony Scheffler.  In the fourth quarter, Pittsburgh managed to tie the game with Roethlisberger completing a 13-yard TD pass to rookie TE Matt Spaeth, along with a 12-yard TD pass to Miller.  Unfortunately, Denver managed to get kicker Jason Elam to nail a last-second 49-yard field goal. Pittsburgh's defense, which had given up only 5 touchdowns in their first 5 games, gave up 3 on the night.. In which quarter did only one team score?