Tom Herman wasn't sure if his offense would be up to the task Saturday night.

Thirty four points later, the first-year Houston coach was feeling much better.

"It felt good that we scored some points," Herman said after junior quarterback Greg Ward accounted for a pair of touchdowns to lead the No. 18 Cougars to a 34-0 rout of Southeastern Conference foe Vanderbilt at John O'Quinn Field at TDECU Stadium in Houston, Texas.

"I was worried going into the game. We had two true freshmen starting at offensive line and a redshirt freshman, so hats off to those guys for coming through for us."

Ward Jr. scored his nation-leading 16th rushing touchdown and threw for another to help Houston remain unbeaten.

The junior quarterback was 15-of-23 for 221 yards and a touchdown and carried the ball 19 times for 33 yards and a score as Houston (8-0) secured its second win over a Power Five conference after beating Atlantic Coast Conference opponent Louisville 34-31 on Sept. 12.

Houston recorded its first shutout over an SEC team since 1969 - a 74-0 thumping of Mississippi State.

"Our defense came to play tonight," Herman said. "We knew we'd have to lean on them a little bit because of how good their defense was, and they showed up.

Vanderbilt (3-5) has lost eight straight games against ranked opponents dating back to 2013.

Cougars senior running back Kenneth Farrow ran for 82 yards and a touchdown on 16 carries and junior wide receiver Chance Allen reeled in three catches for 95 yards and a score. Houston junior wideout Demarcus Ayers also caught a touchdown pass and had 59 yards on five catches.

The Cougars outgained the Commodores 371-185, including 221-44 through the air.

"I apologize for the bad ball tonight," Vanderbilt coach Derek Mason said.

Commodores quarterbacks struggled against an opportunistic Houston defense, as starting redshirt sophomore Johnny McCrary was 2-for-9 with 24 yards and two interceptions and freshman Kyle Shurmur completed 3-of-11 for 20 yards and another interception.

Vanderbilt sophomore running back Ralph Webb totaled 94 yards on 25 rushes.

"We just play with fanatical effort," Herman said of his defense, which forced four turnovers. "Effort creates turnovers. You play with fanatical effort, you run to the ball, and you get multiple, multiple hats to the ball, hitting the ball carrier, good things are going to happen."

Houston pulled away late in the third quarter after establishing a double-digit halftime lead as senior cornerback William Jackson III returned an interception 55 yards for a touchdown.

Farrow's score came on a 15-yard run with less than a minute to go in the quarter, his ninth touchdown run of the year and the 31st of his career to tie Jackie Battle for second place on the Cougars' all-time rushing touchdowns list.

Ward Jr. scored on a five-yard run late in the first quarter, giving the Cougars an early 7-0 cushion.

Three plays earlier, Houston senior safety Adrian McDonald set up the score with an acrobatic one-handed interception of McCrary and returned it 13 yards to the Vanderbilt 5-yard line.

It was McDonald's fourth pick of 2015 and the 17th of his career, setting a school record.

After a 52-yard pass from Ward Jr. to Allen set up a first-and-goal early in the second quarter, the Commodores stuffed a pair of Ward Jr. runs and forced an incomplete pass to hold the Cougars to three points on junior kicker Ty Cummings' 22-yard field goal.

On the next drive, Shurmur's third-down pass was intercepted by Cougars junior outside linebacker Steven Taylor and brought it back 25 yards to the Commodores' 12-yard line.

Ward Jr. found Ayers for an 11-yard touchdown pass three plays later to make it 17-0.

Cummings' 37-yard field goal nearly eight minutes later made it a 20-0 game at the break.

Vanderbilt was decimated by injury in the first quarter, with the Commodores losing freshman offensive lineman Justin Skule and redshirt junior offensive lineman Blake Fromang along with redshirt junior defensive lineman Adam Butler. Skule was carted off, and Butler was taken off in a wheelchair.

Notes: Vanderbilt and Houston met for the first time in the regular season and the second time overall. On Jan. 4, 2014, the Commodores defeated the Cougars 41-24 in the BBVA Compass Bowl. ... The Cougars were one of only four FBS teams entering Saturday's game who ranked in the top 30 nationally in rushing offense (7th, 291.6 yards per game) and passing offense (30th, 269.6 yards per game). ... Cougars senior LB Elandon Roberts had an FBS-leading 56 solo tackles and was fourth in the country in sacks with nine entering play. ... Vanderbilt has scored only nine first-quarter points through eight games this season. ... The Commodores visit 11th-ranked Florida while the Cougars host Cincinnati next Saturday.