San Francisco 49ers cornerback Nate Clements was so happy with the way things were going for the defense Wednesday morning that he voiced his approval.

“They can’t compete,” he said, directing his words at the Oakland Raiders offense. “They’re not at our level.”

For one practice at least, the Niners were on another level, as they had four interceptions in a red-zone passing period at Redwood Middle School. Make that four picks over a sequence of six passes — a staggering turn of events that created all kinds of excitement and emotion among San Francisco players.

Clements got the first interception. Then it was linebacker Diyral Briggs’ turn, followed by cornerback Dre’ Bly, and finally Clements in what was a dominating display of defensive superiority.

“We showed and we put it on film — now we’ve got to come back and play that same way, if not better,” said Clements, whose 14 forced fumbles since 2004 rank tied for first among NFL cornerbacks and tied for 11th among all players during that time span. “I was into it, not just me, but the team. We were into it.”

Clements, who is in his ninth year, said it was the best practice he’s ever been a part of from a defensive standpoint. He said the tone for the joint practice was set earlier in the day by Shawntae Spencer, a cornerback, who engaged in some trash talking.

“I think that got my blood flowing and it kind of rubbed off on everybody,” said Clements. “It was contagious and we were just out there playing with a lot of excitement and still trying to play within the defense.

“The goals we have set for ourselves we accomplished today, as we try to do every practice. We played at a level that they couldn’t match. That’s our goal every time we step on the field.”

The 49ers and Raiders continued with their second and final day of joint practices, which have been beneficial as far as providing added competition for players in different drills — whether it’s 1 on 1’s, 9 on 7’s, offense vs. defense, or the kicking game. It also gives coaches more chances to grade players on film when they’re matched up against an opponent from another team.

“The guys performed at a winning fashion today and they made some plays,” said Greg Manusky, San Francisco’s defensive coordinator. “They’re just playing their roles, their technique, and started having fun with it. It started just building and building and building.”

The Niners have been on a roll of late, with the defense intercepting three passes in a 17-16 preseason win last week over Denver.

By the time they bused back to the Embassy Suites in town late yesterday morning, the 49ers were starting to talk about a swagger that they’ve got going on. In particular, the secondary talks about playing with swagger.

“We were just playing within the scheme,” said free safety Dashon Goldson. “We weren’t showing our defense out there, just moving around a little bit, trying to throw the quarterback off with our coverage. We stepped in the front of a lot of balls. We came out here and got our hands on a lot of balls as a secondary and as a defense.”

In Goldson’s opinion, it was the best practice of camp so far for the 49ers, who continue their exhibition season Saturday against the Raiders at Candlestick Park. It’s a 5:15 p.m. kickoff.

“It was a lot of fun, energy was flowing everywhere, and it kept everybody pumped up about it,” said Goldson. “Everybody wants to make plays. Our defensive line did a good job getting pressure on (quarterback JaMarcus Russell). As a defense, this is good stuff for us, big stuff. That’s what we try to do as a defense — you want to come out here and put your foot down on them. They didn’t really respond well to our defense. We didn’t let up, we kept fighting.

“JaMarcus Russell is a good quarterback — he can get that ball out quick and he can throw pretty hard.”

Manusky prefers to look at the red zone area of the field as “our zone.” Now in his third season of running the 49ers’ defense, Manusky stresses not only getting turnovers, but sacks and hustle to the ball.

“I think you want your whole defense to play with a little bit of swagger,” Manusky said. “It was good to see that and hopefully we’ll keep on building on that. I think that’s a point that we can build on for the season.

“We kept on climbing and trying to make more and more and more, and that’s what they did. It was exciting. They made some plays. Across the board, I think everybody’s playing at a high level. It was exciting to see the defense roll like they did.”

This past year, Manusky oversaw a defensive unit that improved from 25th overall in 2007 to 13th in 2008. The 49ers defense ended the year on a good note, ranking seventh in the NFL in points allowed (17.4 points per game) during the final seven games of the season, while ranking third in passing yards allowed (177.4 yards per game) over the final five games of the year.

Rhythm problem for Raiders

For the Raiders, Russell and Bruce Gradkowski were each intercepted twice in the red-zone drill.

“A little rough at the end there offensively. That’s really on me,” said Raiders coach Tom Cable. “I’m trying to get the quarterback to cut it loose in the red zone. But four picks … probably pushing it a little too much. I have a chance to teach from that and help them get better. The biggest issue is how we’re doing with the red zone right now.”

Cable said the Raiders’ offense was out of rhythm in the scoring zone — which could be an intensity or focus issue.

The coach said he talked afterward with his team about responding to the energy and intensity level shown by San Francisco.

“You’ve got to be able to handle those adversity moments and just get back on the horse and go again,” Cable said. “I don’t think we did a very good job of that. We have to have guys step up.”

The two days of joint practices have been great, said Cable.

“The work’s been awesome. We’re getting so much done in terms of all of the situations.”

Raiders cut Neal

The Raiders announced that they signed safety Rashad Baker and waived fullback Lorenzo Neal.

Cable says the move to cut ties with Neal was made because of the progress Oren O’Neal has made in his rehab from season-ending knee surgery a year ago.

Also, receiver Chaz Schilens underwent surgery on a broken bone in his left foot and is expected to miss four to six weeks.

Coffee impressive

San Francisco coaches like the way Glen Coffee, a rookie running back from Alabama, has looked in camp. Coffee backed it up in the preseason opener, rushing for 67 yards on 14 carries.

“The thing I love about him is his heart,” said coach Mike Singletary. “He’s going to do it until he gets it right.”

So far, Coffee is doing all the right things — showing what it takes to block in pass protection and hit the hole with speed.

“He’s really been exceptional for a rookie running back in terms of all the things that we’ve asked him to learn, the things that he does,” said Jimmy Raye, the team’s offensive coordinator. “I think he’s way ahead of the curve in terms of his pass protection.

“He is mentally tough and he plays physical and rugged. I think he has a bright future. I think what he has is vision and he has the ability to get fast in the hole. I don’t know if in a foot race that he would run that fast, but he has instincts and second-level spurt in the hole. We want him to run the football — that’s his strong suit. He’s a physical inside slasher. He’s shown that in the first exhibition game. If he continues to do that going forward, I think that would be the thing we would lean on.”

Coffee said it’s been a good start to his pro career.

“There’s a lot of things I want to improve on, a lot of things I still need to learn as a rookie,” said Coffee. “But I feel like I’m coming along well.”

Coffee said the No. 1 strength that he brings to the Niners is toughness.

“I believe the coaches will count on me and can count on me in the game with the role that they want me in. I think I bring just another dimension to the offense, just being accountable. I definitely feel I’ve got what it takes.”

E-mail Executive Sports Editor Marty James at mjames@napanews.com or call 256-2223.