PITTSBURGH — It was seemingly a moment to savor for the Dallas Cowboys.

Following a goalline stand by the Cowboys when linebacker Bradie James and safety Keith Davis tackled running back Gary Russell on a fourth-and-goal play at the 1-yard line with 12:20 remaining in the game and with Dallas leading 13-3 Sunday, a silence came over the shocked crowd at Heinz Field.

A timeout was called during a change of possession and all that could be heard were the shrieks of joy from the few Cowboys fans who braved the cold, windy temperatures. Receiver Terrell Owens taunted Steelers fans in the end zone and tight end Martellus Bennett danced along.

It was going to be the exclamation point on what was potentially a season-defining victory.

The Cowboys had gone into a hostile environment and frigid conditions (22 degrees at kickoff) and showed mental and physical toughness. They had answered all the critics' questions.

But the problem was the party wasn't over, and typical for a Cowboys team and season that is defined by their preseason claims of a Super Bowl run, their moment of ecstasy was followed by heartbreak and devastation.

The third interception off quarterback Tony Romo, returned 25 yards by Deshea Townsend for a touchdown, capped a shocking Steelers rally as Pittsburgh scored 17 points in the final 7:15 to escape with a 20-13 win.

"It's tough to swallow this one because we had a good opportunity," Romo said. "We didn't close the deal. This one is on me. I hurt us."

It wasn't the biggest loss of the coach Wade Phillips era. The playoff loss to the New York Giants last year, which ruined a 13-3 regular season, tops this. But it might be the one that signals the end of Phillips' time in Dallas if the Cowboys don't make the playoffs.

"Obviously, it's a tough loss," Phillips said. "We fought hard. I thought our defense played outstanding. We had a lead. We had opportunities and didn't take advantage of it. I was proud of our effort, but certainly not the results."

Yet, the Cowboys (8-5) actually moved up in the playoff rankings, thanks to a loss by the Atlanta Falcons (8-5). If the season ended today, they would be in the postseason as a wild-card team because of a better conference record than the Falcons.

But the Cowboys know they are far from a sure bet with three must-win games to go. They play host to the Giants and Baltimore Ravens before playing at Philadelphia.

What's more is that not only do the Cowboys need to win out, but they must overcome renewed questions about their ability to finish in December. The Cowboys still like the toughness and effort they showed against the Steelers. They played great on defense—recording five sacks, limiting the Steelers to 238 total yards and recovering two fumbles—but couldn't overcome five turnovers on offense.

The Cowboys also acknowledge that this loss could invalidate the confidence the team gained in its recent three-game winning streak.

Said owner Jerry Jones: "I'm crushed. I'm crushed for the players. I'm crushed for the fans. I thought we were going to win this thing and what an achievement it would have been. The loss diminishes and puts a damper on everything."

Like Owens and Bennett, Jones said he thought the Cowboys had the game won after the goalline stand and is still numb to the final rally. The Cowboys gave up two touchdowns in 24 seconds.

It was sparked by a 35-yard punt return by Santonio Holmes, setting up a Jeff Reed field goal to narrow the score to 13-6.

Then quarterback Ben Roethlisberger capped a 67-yard drive with a 6-yard touchdown pass to Heath Miller to tie the score.

Two plays into the next drive, the Cowboys' fate was sealed when Romo threw toward tight end Jason Witten, who slipped. Townsend made the interception and raced untouched to the end zone.

"It was all on me," Witten said. "It wasn't on Tony. It was completely on me. He threw it right where he was supposed to."

Romo went 19-of-36 for 210 yards and three interceptions. He was sacked three times and lost a fumble. His 44.9 passer rating was the third worst of his career.