Coach Mike Shanahan’s much-debated quarterback switch produced eye-catching passing numbers by Kirk Cousins on Sunday at the Georgia Dome but also a too-familiar bottom-line result for the Washington Redskins. They committed seven turnovers, three of them by Cousins, and lost to the Atlanta Falcons, 27-26, when they failed on a two-point conversion gamble with 18 seconds to play.

As the starter that he replaced, Robert Griffin III, looked on from the sideline, Cousins threw for three touchdowns in a 29-for-45, 381-yard passing performance in his second NFL start. He delivered throws on target to receivers running open in the Falcons’ secondary and he injected enthusiasm into a team desperately in need of it.

“It was the first time he had seen some playing time in a while,” said Shanahan, who politely but abruptly left a nearly five-minute postgame news conference after several questions about his job status and media leaks. “So it was nice to see him go out there and play with a lot of confidence. I thought he kept his composure back there and did a heck of a job leading us down the field. I’m just proud of the way he handled himself.”

But Cousins also contributed heavily to the Redskins’ turnover woes by losing a fumble and throwing two interceptions. Tailback Alfred Morris lost two fumbles, one with the Redskins driving inside the Atlanta 20-yard line in the fourth quarter, and wide receiver Santana Moss committed two turnovers, one on a punt return. The Redskins lost their sixth straight game to drop to 3-11.

“Numbers, at the end of the day, don’t really mean a whole lot to me,” Cousins said. “Playing in the Big Ten at Michigan State it wasn’t about numbers. It was about winning. It was about getting the championship. And it’s the same thing here. It’s about winning. But I felt like I was given a chance today to have success. . . . There were just a couple times — two, three, four plays — in the whole game where I made a mistake and it cost us.”

The Washington Post's Jason Reid sees Redskins quarterback Kirk Cousins's performance on Sunday as encouraging, but wonders if he can keep it up against the Cowboys. (Sarah Parnass/The Washington Post)

Cousins’s second interception, by Falcons cornerback Desmond Trufant, set up a 51-yard field goal by place kicker Matt Bryant that extended Atlanta’s lead to 27-20 with just less than 31 / 2 minutes remaining. The Redskins regrouped and got Cousins’s three-yard touchdown pass to Moss and could have settled for a tying extra point and overtime. Instead, Shanahan opted to try for the win. Cousins moved to his right after being pressured on the two-point play and threw an incomplete pass in the back of the end zone.

“We gambled on it and we lost,” Morris said. “It happens. But at the same time, I’m 100 percent with Coach and I’m pretty sure everyone else in this locker room is 100 percent with Coach’s decision.”

The Falcons recovered an onside kick and ran out the clock. They improved to 4-10, with tailback Steven Jackson running for a pair of touchdowns and quarterback Matt Ryan throwing a touchdown pass to tight end Tony Gonzalez.

Cousins threw for 248 yards and two touchdowns in the first half as the Redskins rallied from deficits of 14-0 and 17-7 to lead 20-17 at the intermission. Cousins’s first-half touchdowns went to tight end Fred Davis in the first quarter and wide receiver Pierre Garcon in the second.

Cousins threw the ball well practically from the outset. But the rest of the Redskins’ offense left him on his own against the Atlanta pass rush on a few occasions. Washington had four first-half turnovers. The Redskins and Falcons played at times exactly like two teams headed home for the playoffs, combining for three turnovers on three plays in one second-quarter stretch. Two of those turnovers were by Washington.

“That was weird,” Davis said. “That was like in a video game.”

The Redskins trailed 7-0 before Cousins took the field. The Falcons took the opening kickoff and went on a 14-play, 83-yard touchdown drive culminating with Jackson’s three-yard touchdown run. Cousins lost a fumble on a sack on the Redskins’ opening possession, and the Falcons cashed in on Ryan’s 13-yard touchdown pass to Gonzalez.

But Cousins settled in from there. He found forgotten-man tight end Davis for a 23-yard touchdown set up by a 37-yard dash by Morris. A muffed punt by Moss handed the Falcons a 20-yard field goal by Bryant.

Cousins found wide receiver Aldrick Robinson open behind the Falcons’ secondary for a 62-yard completion. The turnovers came in rapid succession from there. Morris lost a fumble. Ryan fumbled the ball back to the Redskins, but Moss fumbled it right back. Atlanta was forced to punt, and Cousins found Garcon for a 53-yard touchdown. The Redskins, aided by an interception thrown by Ryan, got a pair of field goals by place kicker Kai Forbath in the final minute of the first half to take the lead.

Linebacker Perry Riley Jr. led the charge as the Washington defense stopped Jackson on a fourth-and-goal run from inside the Washington 1-yard line on Atlanta’s first possession of the second half. But the emotional lift for the Redskins was short-lived. A Cousins pass immediately was intercepted by Falcons safety William Moore. Atlanta took over at the 2-yard line, and Jackson scored on a first-down carry.

“You can’t make that many mistakes and win a football game,” Shanahan said.