FOXBOROUGH, Mass. — Patriots rookie runner BenJarvus Green-Ellis had his best game as a pro, Matt Cassel had a solid one and the free-falling Bills had another bad one.

Add a dominating performance by New England's defense, and Buffalo's hopes in the tight AFC East race suffered a serious blow in the Patriots 20-10 win today.

Green-Ellis, an undrafted rookie from Mississippi playing because three running backs are hurt, rushed for 105 yards on 26 carries and scored on a 1-yard run with 1:57 left, his fourth straight game with a touchdown.

Cassel, the steadily improving replacement for Tom Brady, scored on a 13-yard run on the Patriots first series. He directed the offense with poise and completed 23 of 34 passes for 234 yards.

And the defense held the Bills to 58 yards in the second half — while the offense piled up 192. The Patriots had the only two interceptions of the game.

The Patriots (6-3) moved a game ahead of the Bills (5-4), who are 1-4 since winning their first four games. The New York Jets routed St. Louis 47-3 and remained tied with New England.

The loss — Buffalo's 10th straight to New England — was especially harmful to the Bills since they had lost their previous two games against the Dolphins and Jets and dropped to 0-3 in division games. The Patriots are 2-1 against AFC East opponents and face the Jets and Dolphins in their next two games.

After Green's score capped a 19-play drive, the Bills got their only touchdown on a 14-yard pass from Trent Edwards to James Hardy after an 85-yard kickoff return by Leodis McKelvin.

The Patriots scored their first touchdown with help from a 21-yard completion to Wes Welker that moved the ball to the Bills 17. Welker appeared to land with only one foot inbounds before Cassel ran up the middle to score two plays later.

New England stretched the lead to 10-0 on Stephen Gostkowski's 32-yard field goal early in the second quarter. The Bills made it 10-3 on the next series on a 24-yard field goal by Rian Lindell after they reached a second-and-goal at the 4-yard line but lost 3 yards on the next two plays. Then Gostkowski missed a 48-yarder, ending his streak of 10 successful field goal attempts.

But he connected for a 37-yarder on the first series of the third quarter, giving the Patriots a 13-3 lead. Then the defense really clamped down.

On their first series of the third quarter, the Bills failed to get a first down and punted. Their next possession ended in an interception by Deltha O'Neal with 35 seconds left in the quarter. The Patriots couldn't capitalize, though, and lost the ball when Cassel's fumble was recovered by safety George Wilson at the Bills 44.

Buffalo moved to a second-and-5 at the New England 36 but got no further as Ty Warren sacked Edwards for a 6-yard loss and Edwards threw an incompletion, forcing Buffalo to punt.

The Bills played without two of their top defensive players. Safety Donte Whitner was sidelined after separating his shoulder last week in a 26-17 loss to the New York Jets. And pass rusher Aaron Schobel missed his fourth straight game with a foot injury.