BALTIMORE -- Baltimore Ravens quarterback Joe Flacco and his teammates have fallen just short on several fourth-quarter comebacks this season.

So, when Flacco got the ball back with just over two minutes left in a tie game against the San Diego Chargers, he was determined to help his team finally do the celebrating.

Flacco drove the team down the field, and a 39-yard field goal by Justin Tucker with three seconds remaining gave the Ravens a 29-26 victory over the Chargers on Sunday that snapped a three-game losing streak.

Despite the win, the Ravens suffered a major blow when leading wide receiver Steve Smith tore his Achilles tendon late in the third quarter and is out for the season.

"Joe Flacco made plays under duress," Ravens coach John Harbaugh said. "He always plays that way, but he stepped up today and made some plays that were phenomenal football plays that great players make."

Flacco threw a big 18-yard pass to wide receiver Chris Givens on the final drive. The winning kick was then set up by a 21-yard pass interference penalty on Chargers cornerback Steve Williams on a third-and-19 play that gave the Ravens the ball on the San Diego 22-yard line.

Flacco completed 25 of 37 passes for 319 yards. He threw for a touchdown and ran for one.

"It feels good," Flacco said "We don't make it easy."

Chargers quarterback Philip Rivers threw three touchdown passes, including a 70-yard strike to wide receiver Malcom Floyd. Rivers was 28 of 37 for 301 yards. He set a franchise record with four straight games with 300 passing yards or more.

"After the game, I said to Joe (Flacco), 'It's been a crazy year for both of us,' " Rivers said. "That's not a 2-6 team over there. I know the Ravens can say the same things we're saying about penalties and injuries. There's just no easy solution."

The Ravens (2-6) tied the score at 16 on a 48-yard field goal by Tucker on the opening drive of the third quarter. Rivers answered with the 70-yard touchdown pass to Floyd, who blew past safety Will Hill and cornerback Kyle Arrington.

After Tucker's 45-yard field goal pulled the Ravens to 23-19, the defense kept the Chargers (2-6) pinned on their own 1-yard line. Baltimore needed just six plays to go 38 yards and retake the lead on a 1-yard sneak by Flacco with 4:34 left in the game.

San Diego charged back and tied the score at 26 on a 49-yard field goal by Josh Lambo almost two minutes later. However, the Ravens were able to run their two-minute offense to go 59 yards, helped by the penalty on Williams, to set up Tucker's winning kick.

"When we're just trying to win the game, we're getting as close as we can," Tucker said. "We just have to knock it down when we get the opportunity."

The Baltimore defense has gone five straight games without forcing a turnover.

The Chargers had three offensive lineman -- center Chris Watt, guard Chris Hairston and left tackle King Dunlap -- leave with injuries but still managed a 10-6 lead on a 9-yard pass from Rivers to Floyd with 10:16 left in the first half.

On a fourth-and-1, Flacco found wide receiver Kamar Aiken for 3 yards. That set up another 3-yard pass from Flacco to tight end Crockett Gillmore for a 13-10 lead.

Rivers came back with a 13-yard touchdown pass to wide receiver Keenan Allen with nine seconds left, and the Chargers led 16-13 at the break. Ravens cornerback Asa Jackson managed to block the extra-point attempt, and that proved to be a pivotal play in the game.

"We've let some games slip away but we still have to stay with the same fundamentals," Chargers tight end Antonio Gates said. "We have to knock on the door until it opens and turn this thing around."

NOTES: Chargers TE Antonio Gates (hamstring) was back in the lineup after missing last week's game against the Oakland Raiders. Gates, who already served a four-game suspension, was active for just the third time this season. ... Ravens LT Eugene Monroe (shoulder) was scratched after leaving the Monday night game against the Cardinals. It was the 10th game that Monroe has missed during the past two seasons in Baltimore. ... San Diego LB Manti Te'o (ankle) missed his third straight game.