The Washington Post's Mike Jones says the Redskins' loss to the Cowboys in their final home game produced the same errors that plagued them throughout the season. (Natalie Jennings/The Washington Post)

The Washington Redskins added another sad chapter to the debacle that is their 2013 season. Mike Shanahan and his team allowed a nine-point fourth-quarter lead to evaporate and closed out their home schedule with a 24-23 loss to the Dallas Cowboys on Sunday.

A pair of third-quarter turnovers forced by the defense and a record-setting day by wide receiver Pierre Garcon gave Washington hope as the final quarter began at FedEx Field.

But then Washington’s defense had a fourth-quarter meltdown of its own, blowing a 23-14 advantage as they saw Tony Romo shake off a game full of struggles to direct a game-winning scoring drive. The outcome improved the Cowboys’ record to 8-7 and kept their playoff hopes alive. Meanwhile, the loss dropped Washington to 3-12 and gave Shanahan both the first seven-game losing streak and first 12-loss season of his coaching career.

“Any time you have a game like that and you can’t find a way to get it done, especially against Dallas, you just take a look back at your opportunities, and you’re very disappointed you didn’t take advantage of them,” said Shanahan, whose team went 2-6 at home this season.

Nursing a 23-17 lead with 3 minutes 39 seconds left, Washington’s defense seemed poised to seal the victory. They denied Dallas running back DeMarco Murray on second and goal and third and goal, each from the 1-yard line. On the third-down play, Dallas tried to run wide, but Murray met resistance and then skirted backward, trying to reverse field before Perry Riley Jr. dropped him for the loss.

But on fourth and goal from the 10, Romo had time to scan the field with no pressure coming and tossed the ball out to his right, where Murray caught it and spun into the end zone.

“Worst feeling in the world,” Riley said. “Losing is bad, but honestly, me personally, I’d rather how we lost against the Chiefs [45-10] than how we lost today. Fourth and goal on the 10-yard line, you’ve got to get a stop. Got to get a stop and we didn’t. . . . We’re fed up. Everybody on the team is fed up at this point. We should be winning. We need to be winning. We’re not winning. That’s frustrating.”

Next week the Redskins will play the New York Giants looking to avoid 3-13, which would mark their worst record in 19 seasons.

Washington entered the game with nothing but pride on the line. The Cowboys, meanwhile, entered the game with plenty of incentive, needing a victory to keep their playoff aspirations alive.

But dreary first-half performances by both teams seemed to suggest that neither team wanted the game.

After its first possession — a three-and-out — Washington surrendered a 62-yard punt return that set up a three-yard Cowboys touchdown, and it later surrendered a 14-yard touchdown pass from Romo to Dez Bryant. Meanwhile, the Cowboys allowed the Redskins to move the ball up and down the field. Washington outgained Dallas 181-120 and dominated time of possession 20:21 to 9:39 in the first half. But the Redskins faltered in scoring position and had to settle for field goals.

Late in the second quarter, Washington reached the Dallas 28-yard line, but Kirk Cousins threw an interception on a pass intended for Santana Moss. The throw was high and behind Moss, who tried to twist and get his hands on the ball but instead tipped it to safety Jeff Heath at the 7-yard line.

“Santana did a good job breaking in, and I threw it a little bit more upfield,” Cousins said. “That’s where you talk about chemistry, you talk about reps. . . . It’s a game of inches. I’d like to think down the road, I’m going to know where he’s going to go and I’m going to anticipate that a little better.”

Dallas led 14-6 at halftime, but Washington rebounded in the third quarter, looking like the team with postseason aspirations.

The Redskins’ defense forced turnovers on their first two stands of the second half, and the offense responded by scoring touchdowns off each to take a 20-14 lead with four minutes left in the third quarter.

Three plays into the second half, Romo dumped the ball off to Tyler Clutts. Redskins cornerback Josh Wilson, five inches shorter and 66 pounds lighter than Clutts, hit the fullback at the line and knocked the ball loose. Wilson recovered the fumble and gave his team the ball at the Dallas 33.

Seven plays later, Cousins connected with Garcon on an eight-yard slant route into the end zone for his team’s first touchdown of the day and Garcon’s fifth of the season.

With his team up 14-13, Romo looked to direct a scoring drive to give them some breathing room. But instead he threw an interception to DeAngelo Hall.

Hall had Bryant heavily covered and came back to the ball while Bryant slipped. Hall made the easy catch and returned it six yards to the Dallas 47, where Washington took over.

The Cowboys had no answer for Washington’s rushing attack on the ensuing drive. In the final four plays of the possession, Redskins offensive coordinator Kyle Shanahan called Alfred Morris’s number four straight times. Morris gained nine, six, seven and four yards, respectively, the last carry resulting in a touchdown that, following the point after, put Washington up 20-14.

On that series, Cousins completed a 19-yard pass to Garcon, which gave the wideout his 107th catch of the season and broke the franchise single-season reception record that Art Monk set in 1984.

A 47-yard Kai Forbath field goal on the first play of the fourth quarter extended Washington’s lead to 23-14. But that nine-point advantage wasn’t enough.

The Cowboys showed signs of life for the first time in the second half as they generated a 15-play, 73-yard drive. But they had to settle for a Dan Bailey field goal after an incomplete pass from Romo to Bryant in the back of the end zone.

The Redskins sputtered offensively after that, nudging the ball only 19 yards in six plays over 2:30 and had to punt.

Then came a nine-play, 87-yard drive capped by the 10-yard touchdown pass from Romo to Murray that gave Dallas a 24-23 lead with 1:08 left.

“Everybody wanted it,” Bryant said of his team’s winning drive. “It was in their eyes. It makes you feel like there are no worries. Get those couple stops, the offense is going to drive it down there and score. We are going to do what we need to score. That’s what we did.”

On Washington’s final chance, three straight incompletions from Cousins doomed the Redskins. The second-year quarterback ended the day having completed 21 of 36 passes for 197 yards, a touchdown and an interception. Romo, meanwhile, saved his best for last. After entering the fourth quarter with only eight completions for 86 yards, he completed nine of his last 12 passes for 140 yards and a touchdown.