OAKLAND, Calif. -- Derek Carr took little time to build up his rapport with rookie receiver Amari Cooper.

Carr completed three passes to Cooper on an opening field-goal drive and the Raiders beat the St. Louis Rams 18-3 in their exhibition opener under new coach Jack Del Rio.

"It was awesome," Carr said. "I knew I wanted to get him some touches. I want to get him as many as we can in the preseason. That way he just gets the feel for it and all those things."

Carr kept looking for Cooper and threw an interception to Trumaine Johnson in the end zone on the second drive before turning the game over to the backups.

"We're very happy it happened now and not in the regular season," Carr said. "That's what the preseason is for. We'll go back and clean that up and make sure for years to come we clean that up."

Cooper, the fourth pick in the draft, finished with three catches for 22 yards and added a 3-yard run on an end-around as he tries to become the game-breaking receiver lacking in Oakland the past decade.

The Raiders have not had a 1,000-yard receiver since Randy Moss in 2005. They added Cooper and Michael Crabtree this offseason in hopes of changing that. Crabtree caught two passes for 15 yards.

Nick Foles drove the Rams to a field goal on his first drive with the team, but left after the second drive. Foles completed his first two passes to Lance Kendricks and Tavon Austin for 61 yards before the offense stalled.

Observations from the game:

ROOKIE WATCH

Rams: First-round pick Todd Gurley sat out as he recovers from a knee injury that ended his college career. Undrafted cornerback Imoan Claiborne intercepted a pass from Ponder to end the first half.

Raiders: Third-round tight end Clive Walford also made a strong debut despite missing most of camp with an injury. Walford caught two passes for 28 yards. Fifth-round linebacker Ben Heeney had eight tackles and a sack.

BIG PLAY BACKUPS

The Raiders got strong play from their backup quarterbacks. Second-stringer Christian Ponder went 6 for 9 for 59 yards and a 3-yard TD pass to Andre Holmes. Third-stringer Matt McGloin completed 10 of 11 passes for 104 yards with a 16-yard TD pass to Brice Butler.

INJURY REPORT

Rams: Guard Rodger Saffold left on the opening drive holding his right arm and did not return. Linebacker Daren Bates left with an undisclosed injury in the second quarter. Coach Jeff Fisher had no updates on their conditions.

Raiders: Among the Raiders held out with injuries were receiver Rod Streater, linebacker Sio Moore, running backs Roy Helu Jr. and Jamize Olawale and tight end Lee Smith.

FLAG DAY

The Rams looked sloppy at times with 10 penalties for 75 yards. The Raiders were much cleaner with just two for 22.

INSPIRATIONAL

Army veteran Daniel Rodriguez made his NFL debut when he returned a kickoff in the second half for 23 yards. He added a 6-yard punt return and a 3-yard catch. Rodriguez earned a Purple Heart and Bronze Star Medal with Valor Device for his service in Afghanistan.

"It was definitely surreal to come and compete up here," Rodriguez said.

HISTORY IN THE BOOTH

Beth Mowins did the play-by-play broadcast on the Raiders' local telecast, joining Gayle Sirens as the only women to call an NFL game on television. Sirens did a regular-season game for NBC in 1987.

QUOTABLE

Rams: "It was great to have a fast start, move the ball downfield. We were executing, converting on third down, getting a lot of first downs. When we get in the red zone, those situations we've got to come away with touchdowns," Foles said.

Raiders: "It was an excellent night It was a clean night. We came out relatively healthy and got some good work. I'm overall pleased with the effort," Del Rio said.

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