San Diego — Five seconds left, down by three points and the ball inside the 1.

The Pittsburgh Steelers needed a gutsy play against the San Diego Chargers.

They got it for a stunning victory.

Le'Veon Bell scored on a wildcat run as time expired to give Mike Vick and the Steelers a rousing 24-20 victory Monday night.

Bell took the direct snap, ran left and was slowed in traffic before diving for the end zone and getting the ball across the line as Donald Butler dragged him down.

"'I got to get it in," Bell said. "We still had a timeout left. I was thinking we still have a timeout left, so I'm thinking, 'OK, maybe if I get stopped, maybe run like 4 seconds off and get a timeout and we could kick a field goal. I wanted to end the game right there.

Bell said it was the most meaningful touchdown of his three-year career. "The game-winner on the last play of the game, that's what you dream about," he said.

Tens of thousands of Pittsburgh fans waving Terrible Towels roared as the Steelers improved to 3-2. San Diego dropped to 2-3.

Vick, having an awful game until the fourth quarter, kept the drive alive with a 24-yard scramble up the middle on third-and-6 from the 41 and then a 16-yard pass to Heath Miller to 1 a play before Bell's big run. An unnecessary roughness call against San Diego's Jahleel Addae moved the ball a half-yard closer to the end zone and stopped the clock.

"It's not how you start. It's how you finish," Vick said.

San Diego called a timeout before Pittsburgh ran the gutsy play.

Bell ran 21 times for 111 yards.

San Diego rookie Josh Lambo kicked a go-ahead, 54-yard field goal with 2: 56 left.

Vick, making his second straight start in place of injured Ben Roethlisberger, couldn't get much going until he and Markus Wheaton hooked up on a 72-yard touchdown on a stop-and-go route to tie it at 17 with 7:42 left.

The Chargers then moved down the field for Lambo's kick. Eight days earlier, the rookie kicked a 34-yarder as time expired for a 30-27 win over Cleveland. Lambo also was short and left on a 60-yard attempt just before halftime against the Steelers.

Antonio Gates returned from a four-game PED suspension and caught a 12-yard scoring pass from Philip Rivers in the first quarter and then had an 11-yard grab with 8:02 left to give the Chargers a 17-10 lead. Gates has 101 career TDs, joining Tony Gonzalez (111) as the only tight ends to reach that milestone.

Rivers has thrown 74 touchdown passes to Gates, the most from a QB to a tight end in NFL history.

Gates was suspended without pay for testing positive for a performance-enhancing drug in the offseason.

Rivers didn't waste any time going to Gates on San Diego's first possession, completing passes of 10 and 12 yards to the tight end. A 31-yard completion to Danny Woodhead and a 15-yard facemask penalty on the Steelers moved the ball to the 16. Two plays later, Rivers hit the wide-open Gates for a 12-yard TD.

Antwon Blake intercepted Rivers' pass and returned it 70 yards for a touchdown to give the Steelers a 10-7 lead late in the third quarter. Receiver Malcom Floyd broke off a crossing route that led to the pickoff.

It was Rivers' third pick-six of the season. He has turnovers in 10 of his last 11 games.

San Diego came right back and tied it on Lambo's 40-yard field goal.

Rivers was 35 of 48 for 365 yards.