For most of the season, Marshall running back Devon Johnson had been the main engine driving one of the top rushing offenses in college football.

But after hurting his left knee last week, Johnson remained on the sideline when the No. 23 Thundering Herd visited Southern Mississippi on Saturday night.

Marshall never missed a beat.

Running back Remi Watson scored four touchdowns and quarterback Rakeem Cato threw for two scores and ran for another as Marshall rolled to a 63-17 victory over the Golden Eagles.

The Thundering Herd (9-0, 5-0 Conference USA), who fell behind 14-0 before taking an offensive snap, rushed for 335 yards and seven touchdowns.

"Devon probably could've played, but I watched him during warmups and didn't like his body language," Marshall coach Doc Holliday said. "But I was pleased with the way that our guys went out there and played."

Holliday was particularly pleased with Watson, who got the start and rushed for 49 yards and three touchdowns on 17 carries. He also caught the first scoring pass of his career.

"It was great to see Remi make the plays to the numbers on the board," Holliday said. "He's a big, physical guy, and it's nice to see him make plays."

Marshall extended its best start to a season since an unbeaten run in 1999 by beating Southern Miss for the fourth consecutive year.

The 63 points were the most allowed by the Golden Eagles (3-7, 1-5) since a loss to Brigham Young in 1976. Marshall is the only FBS team to score at least 35 points in every game this season.

"The explosive plays came at the end," Southern Miss coach Todd Monken said.

Monken said Cato's ability to make plays running with the ball hurt the Golden Eagles.

"A couple of times he pulled it and ran with it, which he is capable of," Monken said. "That is where they came, and that is where they are going to come, those plays, when he breaks you down or when the game gets to a point where you are just a hair down from an energy standpoint or a detail standpoint."

Behind Johnson's 150 yards per game, Marshall came in ranked sixth among FBS schools at 290.6 yards rushing a game.

His teammates more than picked up the slack.

Watson scored twice on 7-yard runs as well as a 1-yard pop. He also caught a 2-yard touchdown pass.

Steward Butler ran for a game-high 118 yards on just five carries, including touchdown runs of 83 yards and 30 yards.

Cato added 92 yards on nine carries, including a 10-yard score. Tony Pittman capped the scoring with a 26-yard scoring run with less than 3 minutes left.

Cato completed 13 of 19 passes for 186 yards, including 2-yard scoring passes to Watson and Tommy Shuler.

Southern Miss running back Ito Smith, who rushed for a career-high 141 yards on 27 carries, put the Herd in a 14-0 hole with a pair of 2-yard touchdown runs as the Golden Eagles started the game with a bang.

Southern Miss drove 75 yards after the opening kickoff, then went 56 yards after recovering an onside kick.

After the second score, Southern Miss recovered another onside kick, but that was nullified when a player away from the ball was flagged for being offside.

"We had a plan that if we scored early in the game, we were going to onside kick until they recovered it," Monken said. "If we would have gotten that other one, we would have kicked another one after we scored.

"We are not good enough in one given area to compete against a team like that."

As it turned out, Monken was right. The Golden Eagles couldn't keep pace with the Herd, and Corey Acosta's 35-yard field goal in the second quarter produced the only other points for Southern Miss.

Marshall's offense didn't take its first snap until there was 5 minutes, 44, seconds, left in the first quarter.

But when it did, Cato drove the team 62 yards on 12 plays, capping the march with a 2-yard pass to Watson in the front corner of the end zone while scrambling to his right.

A 25-yard punt set up the Herd at midfield near the end of the first quarter, and it took Marshall two plays to cover the distance. Cato hooked up with Shuler for 20 yards on the last play of the period, and Butler ripped off a 30-yard run to tie the score on the first play of the second quarter.

Southern Miss gave Marshall another short field when the Golden Eagles failed on fourth-and-1 from their 34-yard line.

Five plays later, Watson gave Marshall the lead for good with a 7-yard run, and while the Golden Eagles were able to get back to 21-17 on Acosta's field goal, the Thundering Herd answered immediately on Cato's pass to Shuler for a 28-17 halftime lead.

Cato added to his own FBS record by throwing a touchdown pass in his 41st consecutive game. He also passed Chad Pennington on the school's career list for total offense and pass attempts.

Southern Miss quarterback Cole Weeks made a second consecutive start in place of Nick Mullens, who has missed the past 11 quarters after spraining his foot in the first quarter on Oct. 25 against Louisiana Tech.

Weeks completed 11 of 19 passes for 114 yards, Southern Miss' season low for passing. He also had a hand in all three of USM's turnovers, throwing an interception on the final play of the first half and losing two fumbles after being stripped of the ball in the pocket while trying to pass.