The second-round pick, whom the Cowboys had 16th on their draft board this spring, had one of those coming-out games in Sunday's 38-35 overtime victory against the Indianapolis Colts.
Lee picked off two passes, returning one for a touchdown, and was credited with four tackles.
"If you would have told me I would have picked off two passes from Peyton Manning, I would have told you were lying," Lee said. "This is a blessing."
The Cowboys' coaches always tell the young players to be ready because they'll never know when an opportunity will present itself.
Inside linebacker Keith Brooking was dealing with a sprained left foot. It was hurting him so badly he wore a larger-than-usual shoe with a plate in it. Brooking should be commended for his toughness, but the Cowboys should also get credit for sticking with Lee.
In training camp, he battled nagging injuries and struggled in pass coverage. There were thoughts that maybe the Cowboys had missed with their second-round pick.
The front office knew Lee could play well against the running attack because he was a strong tackler at Penn State, but most of teams in the NFL pass more than they run.
While Lee struggled, the snap counts for Brooking and Bradie James, the other inside linebacker, went up. Each week the coaches wanted to get more snaps for Lee, but they couldn't until he got better in the passing game.
But over the past few weeks, Lee did get better.
He was involved in four tackles, all solo, in a win over the Detroit Lions on Nov. 21. He also had a tackle for loss and a forced fumble. On Thanksgiving Day, he had only two tackles, but you could tell he was getting better. When Brooking was hurt, Lee got the opportunity for more playing time.
"I tried to put some good weeks together," Lee said. "I'm gaining experience when I get the reps each week and just learning."
On the first interception Sunday, Lee jumped the route as Manning threw a pass to Blair White and returned it 31 yards for a score in the third quarter. It was the first touchdown for Lee since high school.
But he wasn't done for the night. He battled a shoulder problem that needed attention, so he had some extra padding placed under his shoulder pads. Then in overtime, Mike Jenkins tipped a pass with one hand to Lee, who made the catch and returned it 13 yards to the Colts' 36-yard line.
Six plays later, the Cowboys were celebrating David Buehler's game-winning field goal.
"He made a couple of serious instinctive plays out there that there's no way to coach," owner/general manager Jerry Jones said. "He certainly played the best game in my eyes that he's played since he's been here."
There is always talk about players' futures in the NFL, especially when they reach their 30s. Brooking is 35 and James turns 30 on Jan. 17.
It's a primary reason the Cowboys drafted Lee in the second round. They want him to start one day at inside linebacker.
Both James and Brooking have played well enough this year to hold off talk of their demise. Yet when you see how Lee played Sunday, you get the feeling he'll be pushing for a starting job next season.
"We've been saying all along he's a playmaker," Brooking said. "The sky's the limit for him. He just hasn't had a lot of opportunities because he has two studs in front of him. One goes down and he gets more opportunities and makes the best of it. Just keep him healthy. That's the main thing."