Mario Williams and the Buffalo Bills' high-priced defense finally flexed its collective muscle, stuffing the Miami Dolphins in a 19-14 victory Thursday night in Orchard Park, N.Y.

Safety Jairus Byrd forced a fumble and had an interception, and Bryan Scott sealed the victory with his second interception to end the Dolphins' last-gasp drive in the final minute. Williams had one of three sacks for a Buffalo defense that limited the Dolphins to 184 yards.

That more than made up for an offense that lacked finish. Rian Lindell hit four field goals, including a 42-yarder, as Buffalo failed to score an offensive touchdown despite four trips inside the Dolphins 20.

Leodis McKelvin opened the scoring 90 seconds in by returning a punt 79 yards for a touchdown in a game the Bills never trailed.

The Bills (4-6) snapped a three-game skid and won for only the second time in seven games to stay on the fringes of the AFC playoff hunt. Buffalo also ended several other inglorious skids, beating a division rival for the first time in nine meetings and snapping an 11-game prime-time drought that dated to 2001.

Marcus Thigpen scored on a 96-yard kickoff return and Davone Bess had a 2-yard touchdown catch for Miami (4-6), which has lost three straight.

Rookie quarterback Ryan Tannehill continued to struggle for Miami. He finished going 14 of 28 for 141 yards with a touchdown and two interceptions. He was coming off a dreadful outing in which he threw three interceptions in a 37-3 loss to Tennessee last week. The No. 8 pick out of Texas A&M has thrown six TD passes and 11 interceptions.

Williams was supposed to be the defense's centerpiece after signing a six-year, $100 million contract March. He's finally starting to play up to the deal, and his sack gave him a team-leading 51/2.

Broncos: Two-time Pro Bowl defensive end Elvis Dumervil plans to test his sprained left shoulder at practice Friday in hopes the team will clear him to play Sunday against San Diego. Dumervil was injured at Carolina last weekend, but medical tests this week showed no torn muscles or ligaments.

Falcons: Atlanta receiver Julio Jones missed practice for the second straight day with an ankle injury and will be a game-time decision against Arizona. Jones was injured in last week's loss at New Orleans.

Turf lawsuit: Former Houston Texans punter Brett Hartmann has sued the county agency that operates Reliant Stadium, blaming "unsafe turf" for a possibly career-ending knee injury. Hartmann signed with the Texans as an undrafted free agent in July 2011. He played in the first 12 games last season before tearing his left anterior cruciate ligament and fracturing a bone in Houston's 17-10 win over Atlanta on Dec. 4.

Goodell speech: Professional football can evolve into a safer game without sacrificing the physical play -- or, some would say, violence -- that has made it so popular, NFL commissioner Roger Goodell said in a speech on player safety at the Harvard School of Public Health.

"Football has always evolved, and it always will," he told an overflow crowd of a few hundred. "Make no mistake: change does not inhibit the game; it improves it."

In a long-planned appearance that came four days after three starting NFL quarterbacks were knocked out with concussions, Goodell said that the league already has improved the way it handles hits to the head.

The 49ers' Alex Smith, Chicago's Jay Cutler and Philadelphia's Michael Vick all were diagnosed with concussions in Sunday's games. Goodell said that all three were taken out "as soon as they showed symptoms," a claim that was challenged by a member of the audience during the period for questions who noted that Smith and Cutler kept playing for a short time after being injured.

"It was identified and they were taken out of the game," the commissioner said. "Even a few years ago, I'm not sure you would have seen that."