The Dallas Cowboys have used a newfound commitment to the running game to fuel an impressive start.

The Houston Texans are hoping to reignite their own rushing attack to help relieve their playmaking defense.

Coming off another outstanding performance, DeMarco Murray looks to lead Dallas to a fourth straight win Sunday against the visiting Texans.

The Cowboys (3-1) are off to their best start in six seasons behind the NFL's best rushing attack, averaging 165.0 yards per game. Murray leads the league with 534 yards and five TDs, joining Jim Brown, O.J. Simpson and Emmitt Smith as the only players with at least 100 yards and at least one TD in each of his first four games. Brown did it in a record six straight in 1958.

Murray is averaging 5.4 yards per attempt and a league-high 24.8 carries. Smith's 24.5 average in 1994 is the franchise record, while Larry Johnson set the NFL's all-time mark with 26.0 for Kansas City in 2006.

The Cowboys rank second with an average of 32.5 rushing attempts per game -- their highest average since 2005. They ranked 29th with 25.4 rushes per contest from 2006-13.

Murray went for 149 yards and two TDs on 24 carries in Sunday night's 38-17 win over New Orleans, and seemed to open things up for Tony Romo to complete 22 of 29 passes for 262 yards and three TDs.

"I think what you find is that we are consistently doing the same things each week, and in the past we weren't able to do that," said Romo, whose 69.5 completion percentage ties a career high.

The Cowboys must guard against complacency, though. They've been at least two games over .500 in the 12th week or later in each of the last three seasons, but missed out on the playoffs each year with 8-8 finishes.

"We can't let the success get to our heads," said Dez Bryant, who has caught a team-high 23 passes for 291 yards and three scores. "We have to take it game by game, practice by practice and day by day. If we do that, there's no telling what can happen."

The Texans (3-1) have been leaning heavily on an opportunistic defense, which is tied for the league lead with nine takeaways. J.J. Watt returned an interception 80 yards for a touchdown to put them ahead in Sunday's 23-17 win over Buffalo and recorded a career-high nine quarterback hits.

Houston hasn't necessarily been dominant against the run, however, giving up 130.3 yards a game -- making offensive improvement especially paramount.

The Texans ran 23 times for 37 yards against the Bills. They averaged 40.0 carries for 151.5 yards in their first two victories.

"We have to keep making sure that we stick the run in there. We can't just throw it 55 or 60 times a game and get away with that," coach Bill O'Brien said. "We've got to figure out how to run the ball better from a coaching standpoint and from a playing standpoint."

Arian Foster, who admitted he was not at 100 percent (hamstring), tallied just six yards on eight carries. His 0.8 yards per carry marked a career worst as a starter.

O'Brien said Foster continues to be day to day. Alfred Blue would get a majority of the carries if Foster sits out. He ran 13 times for 78 yards when Foster was sidelined in Week 3, but was held to nine yards on nine carries Sunday.

The Texans were also facing one of the league's top run defenses -- Buffalo allows just 71.5 yards per game compared to Dallas' 108.5.

Ryan Fitzpatrick has been intercepted five times in the past two games after going without one in his first two contests while posting a 118.4 passer rating.

He'll look to take advantage of a Cowboys defense beset by injuries. Cornerback Morris Claiborne will undergo season-ending surgery after tearing a tendon in his left knee, while linebacker Bruce Carter will be sidelined with a strained quadriceps.

The linebacking corps has been hit particularly hard, with groin injuries sidelining Justin Durant and Rolando McClain for two games and one game, respectively. Dallas already lost Sean Lee for the season to a torn ACL suffered during organized team activities.

"We've just got a lot of guys that go to work, just practice and want to win," said Henry Melton, who leads the club with 1 1/2 sacks. "It doesn't just take all the big names to be a good defense."

Dallas won the last meeting 27-13 at Houston on Sept. 26, 2010, though Foster had 106 yards on 17 carries.