ARLINGTON, Texas — The Cowboys are a serious NFC playoff contender becauseFelix Jonesis just now hitting his NFL stride.The best three running backs on the field at Cowboys Stadium on Saturday night all wore a blue star on the side of their helmet.Marion Barber, Jones and Tashard Choice no longer are something to be discussed on paper. Rather, they form a triumvirate that can’t seem to lose to the Eagles no matter how many times they line up and play.Jones, the second-year speedster from Arkansas, turned his first NFL playoff appearance into something special. He put himself in the team postseason record book with a 73-yard touchdown run to ice the game for a Cowboys team that hadn’t won a playoff game since Felix was 9 years old.His 16 carries for 148 yards rushing ranks third-best in Cowboys postseason, single-game history, behindTony Dorsett(160) andEmmitt Smith(150). Jones also turned a screen pass into a 30-yard gain.”Give it to the offensive line for making a lot of big holes for the running backs,” Jones said afterward. “It’s a big deal for us (to win this game). It just happens to be the postseason when the best comes out in me.”He grinned at this last remark.This is really a humble guy.”Felix Jonesis so smooth, so subtle, and he can see the whole field,” saidCalvin Hill, former Cowboys running back and the franchise’s first 1,000-yard rusher. “Plus, he’s a great kid.”Tony Romopraised the ground game, as a whole, for “taking pressure off” the offense when it’s trying to take control of a game, as it did Saturday night.The running game, however, is banged up a bit going into Round 2 at Minnesota.Barber was held to three carries for 4 yards because of a bruised left knee that limited his practice Thursday.After the game, fullbackDeon Andersonlimped through the locker room with an ice bag on his right knee.Choice, who received a concussion on his first play a week ago, carried 14 times for 42 yards but left the game a bit woozy in the fourth quarter Saturday night. He said he was OK.”As long as Felix can stay healthy, he’s going to have holes out there,” said Choice, “and when he gets a hole, he makes the most of it.”The jumbo video board showed no one catchesFelix Jonesin the open field. On his 73-yard run, he purposely let the safety get in front of him, then moved him one way and went another.”It was what I saw in my vision,” Felix explained. “I saw green grass.”It didn’t matter Saturday night if it was a second-quarter screen pass for 30 yards or a 73-yard run behind the block of 353-pound pulling guardLeonard Davis. The Eagles and Cowboys have traded places.It used to be the green shirts that had just too many weapons on both sides of the ball.Last Sunday, Jones carried 15 times for 91 yards, and the Cowboys won 24-0. He seems to be getting stronger as the season goes along.”Unbelievable,” said right tackleMarc Colombo, describing the speedy Jones. “The way he hits the holes, and once he gets through the line of scrimmage, he’s the best in the NFL.”With 3:54 left in the game, Felix gave 92,951 of his closest friends a smile and arms extended when he received a friendly pat on the head from Cowboys receivers coachRay Sherman.He played to the crowd.Better yet, he left the Eagles in his dust.

• Ray Buck