OAKLAND, Calif. -- Josh McCown gave JaMarcus Russell credit for lifting the Oakland Raiders' energy level when he stepped on the field to make his NFL debut.

As far as making the plays to beat the Denver Broncos, that was all McCown.

McCown tied his career high with three touchdown passes despite getting booed when he replaced Russell late in the second quarter, and the Raiders capitalized on Denver's mistakes to beat the Broncos 34-20 Sunday.

Russell, the No. 1 overall draft pick out of LSU, made his long-awaited debut in the second quarter. He threw a 16-yard completion to Jerry Porter on his first play and moved Oakland downfield, but was unable to lead the Raiders to any points on his two drives.

"I tried to tell myself just to relax," Russell said. "It's same thing that you do each and every day in practice. That's exactly what it felt like."

McCown was greeted with boos when he came back on the field, but turned those quickly to cheers when his 13-yard touchdown pass to Zach Miller with 50 seconds left in the half gave Oakland a 14-7 lead.

"I just was saying to myself, 'Let's go get another touchdown for our team,"' McCown said. "You understand that's going to happen. I'm happy for him. He's the top pick. He is the future. They've been waiting a while for him to play and they were excited to see him."

Russell entered to a standing ovation with 13:48 remaining in the second quarter. He looked in control for the most part, despite nearly botching a handoff to LaMont Jordan and fumbling a shotgun snap for an 8-yard loss before Sebastian Janikowski was short on a 58-yard field-goal attempt.

Russell drove Oakland to the 25 on his second drive before Justin Fargas was stuffed on fourth-and-1 by D.J. Williams. Russell finished 4-for-7 for 56 yards in his two series.

Russell saw 16 plays of action as coach Lane Kiffin wants to ease him into the NFL slowly after missing all of training camp in a contract dispute. The game was Russell's first since leading LSU to a Sugar Bowl victory over Notre Dame 11 months ago.

"He looked pretty good to me," Denver safety John Lynch said. "He looked poised. He's probably the biggest man I've seen at QB. He looks like he has a fluid arm."

Fargas carried 33 times for 146 yards and a touchdown and Oakland (4-8) snapped a five-game losing streak to Denver (5-7). The Raiders also ended a 12-game home skid to AFC West rivals a week after snapping a 17-game losing streak in the division by winning 20-17 at Kansas City.

"It's big. It's not just another game for us," Raiders cornerback Nnamdi Asomugha said. "Back-to-back AFC West games. That's huge. That's never been done since I've been here. We're taking strides."

Denver lost its second straight to fall two games behind San Diego in the AFC West. The Broncos turned the ball over four times, leading to 24 points for Oakland.

"Interceptions and fumbles, you can't win in this league playing like that," Denver coach Mike Shanahan said. "I'm sure mathematically we're still in it, but we'll have to play much better than we did today if we expect to get into the postseason."

After taking the lead late in the first half, Oakland added 10 more points early in the third. The Raiders scored 17 points in a span of less than five minutes with help from two fumbles by Henry and Thomas Howard's interception of Jay Cutler's pass.

McCown's 13-yard pass across his body to Porter completed the scoring spurt and gave Oakland a 24-7 lead in the third quarter. McCown was hit hard by Ian Gold on the play, prompting Kiffin to run on the field and yell at Denver's Alvin McKinley after the play. Kiffin apologized to McKinley after the game.

"I thought that he was helmet to helmet late against the quarterback," Kiffin said. "I shouldn't have said anything but we're not perfect."

Jason Elam kicked a pair of field goals in the quarter for the Broncos. Henry's 3-yard touchdown run after McCown fumbled a snap from center cut Oakland's lead to 24-20 early in the fourth period.

Janikowski, who missed a 35-yard field goal in the third quarter, hit from 44 yards midway through the fourth. After Fabian Washington intercepted Cutler, Fargas iced the game with a 5-yard run.

McCown completed a 13-yard pass to Justin Griffith on third-and-11 and ran 11 yards on third-and-2 to set up Fargas' score. McCown, starting in place of the injured Daunte Culpepper, finished 14-for-21 for 141 yards and the three scores.

Kiffin said he would wait to decide how he would split up the time for his quarterbacks next week in Green Bay.

Cutler was 16-of-32 for 214 yards and two interceptions. Henry, who missed the previous three games with a knee injury, ran for 49 yards and two touchdowns, but also lost two fumbles.

Notes

• McCown threw a 15-yard TD pass to Tim Dwight on the opening drive, for Oakland's first TD on the opening drive in 36 games.
• The drive was extended by a running-into-the-punter penalty on Cecil Sapp.
• The four turnovers were the most for the Broncos against the Raiders since also having four on Sept. 9, 1990.