IRVING, Texas (AP) _ When the snap went over his head, Tony Romo took off chasing it. When he caught up to the ball, all he did was knock it farther away.

Then things really got interesting.

Finally grabbing hold of the loose ball 33 yards behind the line of scrimmage, Romo dashed back up the left side, followed some blocks and made a nifty move of his own. By the time he went out of bounds, he'd recovered all that he'd lost, plus gained four more, exactly what the Dallas Cowboys needed on a third-and-3 and the spark they needed to beat the St. Louis Rams 35-7 Sunday.

Romo capped that drive with _ what else? _ a 15-yard touchdown run. Then he threw touchdown passes of 59, 37 and 17 yards on his next three series, turning what had been a tight early game into yet another easy win for Dallas (4-0) and another frustrating loss for St. Louis (0-4).

The Cowboys are 4-0 for the first time since 1995, the year of their last Super Bowl title. The Rams are 0-4 for the first time since 2002, when they opened with five straight losses coming off a Super Bowl loss.

Romo was 21-of-33 for 339 yards and three touchdowns, with an interception. He also ran three times for 24 yards, but that's only because his long scramble counted for only 4 on the stat sheet.

It started at the 50, in the shotgun, with center Andre Gurode shooting the ball well above the reach of the 6-foot-2 Romo. The snap landed on the 35-yard line, then kept bouncing. Romo caught up to it at the 28, but was determined to keep the play alive instead of just falling on it, the kind of go-for-broke mentality that drove Bill Parcells batty.

His first grasp was a bobble, setting him up for the kind of embarrassment of his botched hold of a potential winning field goal in the playoffs. The stakes were much lower Sunday, but this game was tied at 7 at the time and the Rams were fired up by an 85-yard punt return by Dante Hall only minutes before. If St. Louis made this tackle, Dallas would have to punt to Hall again.

Romo finally got control around the 17, turned to his left and calmly headed back up the field. Linebacker Raonall Smith had a chance to tackle him near the 30, but Romo juked by and kept going until stepping out of bounds at the St. Louis 46.

The 13 seconds that play took were so mentally and physically draining, a time out was called. By St. Louis.

Five snaps later, Romo took off again, scoring easily with 11 seconds left in the first half. The Cowboys went up 14-7 and wouldn't be challenged again.

The league's highest-scoring offense got rolling from there. Dallas not only scored touchdowns on all three of its third-quarter drives, the Cowboys did so in only 11 plays. Patrick Crayton scored the first two touchdowns and Jason Witten had the third. Dallas' first score of the game was a 2-yard run by Julius Jones.