LANDOVER, Md. — The Dallas Cowboys finally have a handle on their December doldrums.

Now it's time to work on January.

The Cowboys returned to the playoffs last night, pitching a 17-0 shutout in their 100th meeting with the Washington Redskins and setting up an NFC East title showdown with the Philadelphia Eagles.

After starting 0-2 this month, Dallas recovered to win back-to-back December games for the first time since 2003. The latest victory eliminated the New York Giants from playoff contention.

"I think we showed the December jinx is not here," said receiver Roy Williams, who caught a touchdown pass in the first quarter. "Last year, we were in the same situation and didn't get it done. 2009's a different year."

But what about 2010? The Cowboys (10-5) haven't won in January since 2000 and haven't won a playoff game since 1996. Next week they will host the Eagles (11-4) in a regular-season finale with the division crown on the line; the loser will have to settle for a wild-card berth. The NFL has moved the kickoff time from 1 p.m. to 4:15 p.m EST.

"I look at Philadelphia as a playoff game," Cowboys owner and general manager Jerry Jones said. "It's so meaningful to us."

Tony Romo completed 25 of 38 passes with a touchdown, and had his first interception in five games — a reversal from his turnover sprees of Decembers past. Jason Witten had a career-long 69-yard reception to set up a score, and the defense posted the Cowboys-Redskins rivalry's first shutout since Dallas' 27-0 road win Dec. 14, 2003.

Dallas holds a commanding 59-39-2 lead in the 50-year-old series. The Cowboys didn't allow Washington to score a touchdown this year — the other meeting was a 7-6 win Nov. 22 — and they played their part in the Redskins' first winless season in NFC East play since 1994.

"I think they've learned to play under pressure, and I think that's important," coach Wade Phillips said. "It'll come in handy here when we get to the playoffs. But we've got another pressure game next week."

The Redskins (4-11), distracted by more off-the-field news, put on another embarrassing performance. After the game, coach Jim Zorn — widely seen as a lame duck — uttered sentences containing the same adjectives, over and over: "frustrating," "hard," "frustrating," "hard," "devastating," "hard," "very hard," "devastating," "very hard" and "awful."

"I want to get to five wins," he finally said. "It seems frivolous, doesn't it?"

After a 45-12 pasting by the Giants on Monday night, Washington endured a week in which assistant coach Jerry Gray gave confusing answers when asked if he had interviewed for the head coaching job. Then came some noisy Christmas Day tardiness from defensive tackle Albert Haynesworth, who was sent home by Zorn for being late to a meeting.

Haynesworth used that occasion to again complain about the coaching staff — particularly defensive coordinator Greg Blache — but he nevertheless was in the starting lineup last night.

"I think he voiced his opinion. It was unfortunate," Zorn said. "I think we handled it, and I think it was said, discussed and put to rest. We moved on."

Terence Newman's interception led to the Cowboys' first-quarter TD. He returned the ball 9 yards to the Washington 36, setting up Romo's 4-yard scoring toss to Williams.

Witten set up the next score when he got a step ahead of LaRon Landry on a crossing route, a 69-yard completion that moved the ball to the 3. Marion Barber scored on the next play, giving the Cowboys a 14-0 lead in the second quarter.