Highlighted by key plays from linebacker A.J. Hawk and cornerback Brandon Underwood, the No. 1 defense did not allow the No. 2 offense a first down on four straight possessions. Then the No. 1 defense also got the stop against the No. 1 offense in the 2-minute drill as well.

“Just getting in this atmosphere was good for us,” Hawk said. “Not just for me individually but for everybody on the team. Even though it’s only been a week, we’ve been grinding pretty good for a week in camp, and it felt like a game out there tonight. That kind of got everyone going a little bit.

“Obviously it’s still the end of the first week of training camp, and we have a long way to go. But I think we took a little step forward today.”

Hawk spent much of his night in the offensive backfield. He burst through on a blitz to sack backup quarterback Matt Flynn on third down to end one series, and then on the next series he stuffed running back Quinn Porter for no gain.

Later during the 2-minute drill, after the offense had driven all the way to the defense’s 5-yard line, Hawk bounced right off a block by fullback John Kuhn to stop Ryan Grant for a 4-yard loss on third-and-1. The ensuing fourth down pass was incomplete.

Underwood made the biggest play by the first unit, though. Moving up from his nickel cornerback spot to a starter with Charles Woodson taking a rest for the evening, Underwood intercepted a Graham Harrell pass intended for receiver Shawn Gore and returned it about 30 yards for a touchdown.

The takeaway came right after Hawk had stopped Porter at the line, setting up a third-and-4. Gore stopped on a hitch route but Harrell’s throw was off target. Underwood reached back and snagged it, holding on for the type of catch he’s let get away here and there in practice, and then he took off, scoring easily.

“Just for the vets, they have to be able to feel comfortable with everybody out on the field,” said Underwood, who also was credited with four tackles and maintained good coverage on a handful of other plays. “They have to be able to know when whoever’s number gets called, for me, for Pat (Lee) and for Jarrett (Bush) or whoever, that they’re going be ready to perform on Sundays.”

With Al Harris still recovering from reconstructive knee surgery, Underwood has been working as the nickel cornerback, behind Woodson and Tramon Williams, throughout camp so far. He admitted he got off to a slow start learning the defense as a rookie, but everything is clicking a little faster in Year 2.

How much the Packers could count on the second-year corner was brought into question after an off-field incident at Lake Delton, Wis., in June, and even though his legal situation isn’t entirely resolved, he seems to have regained his focus on football.

“You know what, Brandon Underwood is a guy who’s come a long way I think,” quarterback Aaron Rodgers said. “He’s done a nice job for us this camp, and a guy who I think has grown up definitely in the last couple months, and hopefully he’s going to play a big role for us. We’ll need him to continue to improve, and he’s done a good job for us.”

Underwood wasn’t the only young cornerback making a big play, either. When the backup units got their crack at the 2-minute drill, non-drafted rookie Sam Shields got a chance to show off his instincts, and his speed.

Flynn had driven the No. 2 offense to the defense’s 25-yard line but faced fourth-and-14. On that final chance, he tried to go deep down the seam to rookie receiver Chastin West, and Shields cut him off and picked off the pass near the goal line.

The speedster from Miami was then off to the races, getting some good blocks along the left side and then cutting all the way back across to the right side of the field and going the distance for the score.

“It felt good, catching the ball and going six,” Shields said. “Our defensive coordinator, that’s all we talk about is catching the ball. If the ball is in your hands, you have to catch it and score.”

Once Shields cut back and found daylight, there was no catching him. Maybe the fastest player on the current roster, Shields – who played receiver for most of his college career until converting to cornerback as a senior – still has an uphill battle in front of him to make the roster, but he’s also getting a look at punt and kick returner and is hoping to make an impact there as well.

“Shields, he’s a guy who wasn’t even drafted,” Rodgers said. “I was asking ‘Drive’, how does a guy like that not get drafted with that kind of speed and athleticism? And that’s some of the stuff we’ve seen from him in camp so far. It’s exciting what he’s done so far.”

With two interceptions for touchdowns, the defense seems to be picking up where it left off last year, when it led the league in takeaways and scored four times.

“I thought the secondary was aggressive and active and that’s what you want, because when the ball is in the air, as we have demonstrated in the past, we have playmakers on defense that when they get their hands on the football they are able to do something with it,” Head Coach Mike McCarthy said. “That’s a trait that you always look for in our defense and I thought they exhibited that tonight.”