TEMPE, Ariz. -- No. 21 Colorado has won its first four games for the first time in 20 years behind a "Folsom Fast" attack powered by quarterback Steven Montez and breakout wide receiver Laviska Shenault.

Arizona State has begun to define itself as a run-first group, which is new coach Herm Edwards' stated preference.

The clash in styles makes for an interesting contrast when the teams meet in a Pac-12 South game on Saturday at Folsom Field.

The Buffaloes won the division in 2016 before a down year in 2017. Colorado is one of 14 undefeated teams in FBS.

"We have to just keep moving forward," Colorado coach Mike MacIntyre said. "If we keep doing what we want to do, we'll stay ranked. If we don't do what we want to do, we won't stay ranked. It's that simple. Just keep going from there."

The Buffaloes' success starts with the physically imposing Montez/Shenault connection.

Montez, a 6-foot-5, 235-pound junior, has completed 91 of 120 passes for 1,092 yards, nine touchdowns and two interceptions. He is ranked No. 11 in FBS in passing efficiency, and he added 10- and 35-yard touchdown runs in a 38-16 victory over UCLA last Friday.

Shenault, a 6-2, 220-pound sophomore, has 38 receptions for 581 yards and four touchdowns. He leads FBS with an average of 145.3 yards per game, and he broke out early with 211 yards receiving in a season-opening victory over Colorado State on Aug. 31.

"Ever since Laviska got on campus, I think everybody on the team knew that he was going to be something special for us," Montez said. "We all kind of knew when No. 2 gets on the field and starts routing people up, it is going to be tough to stop him."

Arizona State sophomore halfback Eno Benjamin rushed for a school-record 312 yards on 30 carries and scored four touchdowns in a 52-24 victory over Oregon State last Saturday, breaking Benny Malone's game record of 250 yards set in 1973.

Benjamin has 595 yards rushing and five touchdowns in his first season as a starter. He scored on 44-, 47- and 10-yards runs and caught an 8-yard touchdown pass from quarterback Manny Wilkins against the Beavers. Benjamin has 187 yards rushing in the first half, breaking Woody Green's school record for a half.

"We're going to run the football, and I said that when I first got here," said Edwards, who coached NFL rushing leader Curtis Martin during his time with the New York Jets.

"When you run the ball, there is some toughness about you. It travels well, along with defense. Because it doesn't take a lot to turn around and hand it to a guy. It's really hard to mess that one up. And the ball's not heavy. The guy can carry it. So if we can block them, the guy's going to run. From there, everything else opens up."

Benjamin had five carries for 52 yards in Arizona State's 41-30 victory over Colorado last season, scoring the clinching touchdown on a 19-yard run in the fourth quarter after Buffaloes built 10-point lead three times in that game.

Arizona State, ranked No. 23 before consecutive losses to San Diego State and No. 10 Washington, has had the much more difficult schedule coming in.

The Sun Devils moved into the rankings after a 16-13 victory over then-No. 13 Michigan State in the second week of the season before seven-point road losses to San Diego State and Washington.

The Buffaloes have not faced a ranked team.

Wilkins has passed for 1,224 yards and 10 touchdowns with only one interception despite throwing less frequently the last two weeks. He passed for 162 yards and three touchdowns against Oregon State after throwing for only 104 yards in a 27-20 loss to Washington. Wide receiver N'Keal Harry, a preseason AP All-American, has 31 receptions for 419 yards and five touchdowns.

The Sun Devils gave up 261 yards rushing to Oregon State last week, including 254 by Jermar Jefferson, and have allowed an average of 161.6 yards per game.

San Diego State had 311 yards rushing in a 28-21 victory on Sept. 15.

Colorado is averaging 489.8 yards per game total offense (20th in the FBS) and has given up 352 yards per game. Virginia Tech graduate transfer running back Travon McMillian leads the Buffaloes with 392 yards rushing and four touchdowns on 54 attempts.

"They're a fast-moving offense," Edwards said.