Nov. 9 (Bloomberg) -- The New York Giants slumped to their first four-game losing streak in three years as Philip Rivers threw an 18-yard touchdown pass with 21 seconds left to give the San Diego Chargers a 21-20 victory.

The Indianapolis Colts and New Orleans Saints remain the National Football League’s only undefeated teams after pulling out home wins yesterday, while the Tampa Bay Buccaneers beat the Green Bay Packers 38-28 for their first win in almost a year.

The Giants scored 13 fourth-quarter points to overcome a 14-7 deficit in East Rutherford, New Jersey, and then allowed the Chargers to drive 80 yards in one minute, 46 seconds for the winning touchdown. When Vincent Jackson hauled in Rivers’s third scoring pass in the right corner of the end zone, it was the latest tying or go-ahead touchdown the Giants have allowed in a game a since Dec. 2, 2002.

“We felt good about the situation we were in and we let them off the hook,” Giants coach Tom Coughlin said during his post-game news conference.

It was the first one-point home loss in eight years for the Giants, who fell to 5-4 after opening the regular season with five straight wins. The last time the team lost four in a row was Nov. 12 to Dec. 3, 2006. The Giants fell further behind the Dallas Cowboys, who beat the Philadelphia Eagles 20-16 to improve to 6-2 and move into sole possession of first place in the National Football Conference’s Eastern Division.

“We just didn’t make the plays to win it,” said Manning, who passed for 215 yards and two touchdowns. “We’re going to keep working, keep fighting and find a way to win some games.”

The Chargers won their third straight to improve to 5-3.

Rivers vs Manning

The game marked the first meeting between Rivers and Eli Manning, the top two quarterbacks taken in the 2004 NFL draft.

The Chargers drafted Manning with the top pick and traded him to the Giants for Rivers and three draft selections. San Diego used New York’s 2005 first-round pick to acquire linebacker Shawne Merriman, who sacked Manning to end the game.

“Obviously quarterbacks aren’t on the field at the same time. We’re not playing each other,” Rivers said. “But anytime you’re playing a team with a quarterback that’s won a Super Bowl and is the caliber of player that he is, it’s fun.”

The Colts improved to 8-0 with a 20-17 victory over the Houston Texans as Peyton Manning passed for 318 yards and Joseph Addai scored two touchdowns at Lucas Oil Stadium in Indianapolis, Indiana. The Colts blew a 13-3 lead during the second half before Addai’s two-yard touchdown run with 7:11 left in the fourth quarter gave them the lead for good.

Kris Brown missed a 42-yard field goal to the left for the Texans as time expired.

The Saints also improved to 8-0 by overcoming a 17-6 halftime deficit in a 30-20 win over the Carolina Panthers.

Saints’ Defensive Score

Pierre Thomas and Robert Meachem scored third-quarter touchdowns for the Saints, who sealed the victory when Anthony Hargrove forced a fumble and recovered the ball for a touchdown with two minutes remaining.

It was the seventh defensive score of the season for New Orleans, which has won its first eight games for the first time in franchise history.

The Buccaneers improved to 1-7 yesterday as rookie quarterback Josh Freeman threw three touchdown passes at Raymond James Stadium in Tampa, Florida. Freeman tossed a seven-yard touchdown pass on fourth down to give the Buccaneers a 31-28 lead with 4:14 left and Tanard Jackson scored on a 35-yard interception return with 35 seconds remaining to clinch the team’s first win since Nov. 30.

Five for Warner

The Arizona Cardinals beat the Chicago Bears 41-21 as quarterback Kurt Warner tied a career best with five touchdown passes at Soldier Field in Chicago, a week after throwing five interceptions in a loss to Carolina.

Randy Moss hauled in a 71-yard touchdown pass from Tom Brady as the New England Patriots beat the Miami Dolphins 27-17 at Gillette Stadium in Foxboro, Massachusetts. It was the 140th career touchdown reception for Moss, who tied Terrell Owens for second place all-time behind Jerry Rice (197).

In other NFL games during Week 9 of the regular season, it was Atlanta 31, Washington 17; Cincinnati 17, Baltimore 7; Seattle 32, Detroit 20; Jacksonville 24, Kansas City 21; and Tennessee 34, San Francisco 27. In tonight’s game, the 6-1 Denver Broncos host the defending Super Bowl-champion Pittsburgh Steelers, who have a 5-2 record.

To contact the reporter on this story: Erik Matuszewski in New York at matuszewski@bloomberg.net

Last Updated: November 9, 2009 00:03 EST