The Denver Broncos were reeling. Playing at home three weeks ago, with a capacity crowd crammed into one of the noisiest stadiums in the NFL, the only sound the Broncos heard as they headed to the locker room at halftime were boos cascading from every corner of Invesco Field. They trailed the San Diego Chargers 14-3 and were looking like a team only two quarters away from an 0-2 start.

It took only one play to reverse that trend -- the very first play from scrimmage in the second half. Cornerback Champ Bailey had done his homework on San Diego quarterback Drew Brees, and when he saw the offensive formation the Chargers had deployed, he knew exactly where Brees was going to throw the football. Playing well off the intended receiver, at the snap of the ball Bailey jumped the pass route, intercepted Brees's throw and went 25 yards for a touchdown many Broncos believe turned around the game. Whether it changed the season remains to be seen.

"That's why you pay a guy that type of money," Denver Coach Mike Shanahan said after Denver's 20-17 victory. "He has those instincts. . . . That's what great players do."

Added running back Mike Anderson: "What changed our season? Champ. That interception gave us a sense of hope. And if you believe, anything can happen."

The Broncos have won three straight since a season-opening upset loss in Miami and take a 3-1 record into their game Sunday against the 3-0 Washington Redskins, Bailey's team for the first five years of his career. A controversial trade after the 2003 season sent Bailey and Washington's second-round choice in the 2004 draft to Denver for another Pro Bowl player, running back Clinton Portis. Sunday will mark the first time the teams have played each other in the regular season since that deal.

While the Broncos made it to the playoffs with Bailey a year ago, the Redskins struggled on offense in Portis's first season in Washington and finished 6-10. Though Portis went 64 yards for a touchdown his on first carry last year and gained 1,315 yards, he only had five rushing touchdowns and has none this season. In his first two years in Denver, Portis ran for 29 scores and had back-to-back 1,500-yard seasons, with 18 100-yard games in his 29 starts. In Washington, he has had six 100-yard games in 18 starts.

The consensus around the NFL is that both teams benefited from the trade, but the Broncos probably have had the better of the deal so far, if only because of that extra second-round pick in the draft. Denver used that choice, the 41st overall, to select Oklahoma State's Tatum Bell, now a key man in the team's running back-by-committee approach. Bell has Portis-like explosive speed and elusive moves.

"On the surface, Denver did better because they got a Pro Bowl corner and a second-round pick," one AFC general manager said. "They gave up a pretty good back, but they've always proven they can win with any number of running backs. They did it last year and they're doing it again now."

In Bailey, the Broncos had their first Pro Bowl cornerback in 18 years, even though for the second straight season they were bounced from the playoffs by the Indianapolis Colts. Even with Bailey in the lineup last January, Colts quarterback Peyton Manning torched Denver for five touchdown passes, several on Bailey's side of the field, and Manning had an astounding 158.3 passer rating.

But the Broncos still believe Bailey's presence will pay off. They have a shutdown cornerback, perhaps the best corner in the NFL, capable of covering an opponent's lead receiver one-on-one. This allows more flexibility both in pass coverage as well as freeing another safety to help in run support. Bailey's single-coverage skills often allow the Broncos to put seven or eight men near the line of scrimmage to defend the run, as Portis likely will see often on Sunday.

"Their defense is definitely better because of" Bailey, said another AFC personnel director. "He makes plays a lot of corners can't. . . . If you have a shutdown corner, teams also have to go the other way, so you take away a good piece of the field. He makes the linebackers better, he makes the defensive line better."

Shanahan has been able to develop running backs. In his 11-year tenure with the Broncos, four backs (Terrell Davis, Anderson, Olandis Gary and Portis) selected after the first round have gained more than 1,000 yards in a season. He also has said one of the major reasons he wanted to make the trade for Bailey came from his recollection of the impact cornerback Deion Sanders had in 1994, when the 49ers added him and won their last Super Bowl, with Shanahan as their offensive coordinator.

"In the end," Shanahan said that when the Bailey-Portis trade was made, "I just knew we could find a back -- we always have. You look at history, and the corner has made a difference."

Bailey may well have made the same sort of difference in the Redskins' defense last season if he had stayed in Washington. But he had grown frustrated with three different head coaches, five defensive coordinators and their systems, the constant losing and haggling over a new contract. His deal was up after the 2003 season, and when negotiations broke down and the Redskins made him their franchise player, it only added to his misery. There was even some talk that he might be a training camp holdout, something the Redskins wanted to avoid in Coach Joe Gibbs's first season.

In Denver, Portis still had two years left on the contract he had signed as a rookie, a four-year, $2.5 million deal that would have paid him about $750,000 over the last two years. Shanahan was concerned that if a deal to extend his contract could not be worked out that Portis might become a locker room distraction.

Both players benefited financially from the first swap since 1972 of players who had both been in the Pro Bowl the previous year. Portis got an eight-year, $50.5 million deal that included a $17 million signing bonus. Bailey got a nine-year, $63 million contract that makes him the highest-paid cornerback in the league, with an $18.5 million signing bonus.

Asked about the trade, Shanahan described it as "win-win for both teams" and that "both sides are very happy with the trade. . . . Champ handles himself like a pro's pro, the way he practices every day. He's played extremely well for us, he's been exceptional."

Said Gibbs: "It worked out well for both teams. But both teams are focused on their team, not the individual. Clinton is a guy who backs it up. He's got a great funny bone, but when he plays, he's a got a great passion for football. It shows up in pass protecting. He's very aggressive. He probably doesn't like practice, but he loves playing."

Both players said they see the trade as a push and that their major concern is getting a victory, though it's also obvious they'd like to make a significant impact against their former teams.

Bailey, whose status for the game is questionable because of a hamstring injury, described the Redskins as "just another opponent in our way. I don't try to get involved too emotionally. I don't want to get caught up in the hype."

Still, he also admitted he "loves" being in Denver and that "as long as we're winning, I'm happy. I don't like to lose, and that's all we did my years there [in Washington]. This was a good opportunity to go to a good team.

"Some guys have been here 8, 9, 10 years. You always know who the core players are around here. You know who the coach is. I'm definitely getting used to the stability, and I love it. Things are different. The way the organization is run is different. It's stable. There's not a lot of in and out."

Portis also has adapted to the point where Gibbs often describes him as one of his team's leaders.

"He has a great personality," Redskins quarterback Mark Brunell said. "He's great in the locker room. The guys have a lot of respect for him and enjoy being around him. Even though he may not be getting the ball sometimes, he'll go block downfield and [block] for the quarterback. He always goes 100 percent, which is very impressive."

While Bailey said he has few friends left on the current Washington team, Portis maintains close contact with a number of his former teammates. He called wide receiver Rod Smith after Smith was knocked out Sept. 26 against Kansas City and left him a needling message, prompting Smith to say "he was dogging me about getting knocked out, but I'm gonna knock him out."

Former teammate Al Wilson, the Broncos' middle linebacker, also may have given Portis a bit of incentive when he told the Denver Post: "I've played with five or six 1,200-yard rushers since I've been in Denver my seven years. Not to take anything away from the running backs, but you could put anybody in there. I think I could get out there and run for 1,100 yards behind that offensive line."

Portis bristles at such talk.

"Any random guy is not going to make that system," he said. "You have to get a guy with heart. You have to get a guy with attitude. I think I brought more than just my athletic ability. I brought laughs. I brought joy. I brought attitude and a swagger that's hard to find. You can't talk me out of my confidence. I know that what I've got is a gift."

Redskins running backs coach Earnest Byner knows there's no question Portis will have on a serious game face against his former team. "You always want to have a good showing against your old team," Byner said. Said Portis: "It's really not about me. We've been spreading the ball around. As long as everyone is playing and paying attention, you get away from that me-me-me role. I'll still be looking to come out and do something spectacular, but my overall goal is to get out of Denver with a win."

Staff writer Jason La Canfora contributed to this report.

Running back Clinton Portis "is a guy who backs it up," says Redskins Coach Joe Gibbs. Denver Coach Mike Shanahan on Champ Bailey: "He's played extremely well for us."In his two years in Denver, Clinton Portis had back-to-back 1,500-yard seasons, with 18 100-yard games. In Washington, he has had six 100-yard games.