Saturday is Opening Day for the college bowl season. Four games are on tap, and as the day winds down, the NFL goes primetime. Two 9-5 teams very much in playoff contention, the Baltimore Ravens and Dallas Cowboys, will play the final regular-season game at Texas Stadium.

A home win by the Cowboys may be the only chance that a postseason game delays Texas Stadium’s retirement. Saturday’s matchup features two teams that are winning, with defenses that have been instrumental to recent success.

The Ravens had won seven of their last eight contests before losing a defensive showdown to the Steelers, 13-9, last Sunday. After losing three of four games in the middle of the schedule, the Cowboys have won four of their last five, including a convincing 20-8 victory over the NFC East-leading Giants last week.

Neither Baltimore nor Dallas has allowed a rushing touchdown over the last five weeks. The Ravens haven’t given one up since the first quarter of a 30-10 loss to the defending NFL champs on Nov. 16. In the four games since losing to New York, the Baltimore defense has allowed just one touchdown, via the air, and the Ravens have three wins and a low-scoring loss to the Steelers to show for it. The Ravens have given up just three rushing touchdowns all season.

The Cowboys also haven’t given up a rushing touchdown since losing to the Giants -- a 35-14 defeat on Nov. 2. Among all NFL clubs, the Ravens and Cowboys have the longest streaks of opponent rushing attempts without allowing a rushing touchdown.

Opponent Rushes without a TD -- Longest Active Streak

Baltimore Ravens. . . .109
Dallas Cowboys. . . . . 104
Minnesota Vikings. . . .92
Arizona Cardinals. . . . 84
Pittsburgh Steelers. . .76

The Giants picked apart the Cowboys defense that day, but since then, it has allowed a total of just four touchdowns in five games -- all through the air.

The Ravens will have to find a way to move bodies at the line on Saturday. No team has been more committed to the run this season, as they have rushed on an NFL-high 56.1 percent of their offensive plays. Often with less than astounding success.

Rookie QB Joe Flacco has been a pleasant surprise, throwing for 12 touchdowns during Baltimore’s current 7-2 surge. He’s coming off one of his worst performances of the season, and he faces a Dallas defense that leads the league with 53 sacks.

The key on Saturday will be the Baltimore defense. In last nine games, the Ravens have held opponents to fewer than 14 points seven times.

The defense should provide a stiff challenge for the Dallas offense. Only the Giants have logged as many as 100 rushing yards in a game against the Ravens this season, and the Cowboys’ No. 1 back, Marion Barber is a game-time decision whether he’ll play. He missed the Cowboys’ loss to Pittsburgh two weeks ago with a dislocated toe, and wasn’t a factor in last week’s win over the Giants. Barber hasn’t practiced with the team this week.

Rookie Tashard Choice has played well in Barber’s absence. Choice had 166 all-purpose yards against the Steelers, and recorded another 143 and scampered 38 yards for a touchdown versus the Giants.

The Cowboys were sputtering without QB Tony Romo six weeks ago, when he was out with a broken pinkie, but they have won four out of five since his return. He’s thrown 10 TD passes in this stretch. With Barber most likely out, Romo, who is nursing a sore back, may have to take to the air to win the regular-season finale at Texas Stadium.