FOXBOROUGH, Mass. >> LeGarrette Blount wasn’t satisfied with three short touchdown runs, not against a team coming off the second greatest comeback in playoff history.

So the 250-pound back who makes long runs routine took off on a 73-yarder and carried the New England Patriots to their third straight AFC championship game with a 43-22 victory over the Indianapolis Colts on Saturday night.

Suddenly, the ground game has replaced Tom Brady as the heart of the Patriots’ offense.

"Once I get into the open field, they’re going to have to chase me," Blount said. "And if they catch me, they do. And if they don’t, they don’t. They usually don’t."

They didn’t two weeks earlier when he scored on runs of 36 and 35 yards in the regular-season finale against Buffalo. He also returned kickoffs 83 and 62 yards in that 34-20 victory that gave New England a first-round bye. And they didn’t on his long touchdown that gave the Patriots (13-4) a 36-22 lead early in the fourth quarter against the Colts (12-6).

The Patriots will face the winner of the game Sunday between the Broncos and Chargers. It will be in Denver if the Broncos win, and New England will host it if the Chargers win.

"It’s just a great achievement," Brady said. "People have counted us out at times this year, but I think we’ve got a locker room full of believers."

Blount tied Curtis Martin’s team playoff record of 166 yards rushing, on 24 carries, two weeks after rushing for a career-high 189.

"He’s got that combination of size, power and quickness and speed," Patriots coach Bill Belichick said. "He can run hard. He can make guys miss and he can go the distance."

Blount scored on three 2-yard runs in the first half, then burst through the right side for his 73-yarder. Once he reached the end zone, he placed the ball gently on the ground made soggy by a game-long rain.

On the next series, Luck threw his third interception and the Patriots capitalized with Stevan Ridley’s second touchdown run, a 1-yarder that finished the scoring with 11:12 left.

"I’m just disappointed in myself," Luck said. "I can’t commit that many turnovers and have a chance to win against a great team like this."

Blount joined Ricky Watters, who had five touchdowns for San Francisco on Jan. 15, 1994, as the only players with four or more in a playoff game. The Patriots six rushing touchdowns tied the 49ers’ total in that game for second most in playoff history.

Blount’s performance came two weeks after he ran for 189 yards and returned two kickoffs for 145 in a 34-20 victory over Buffalo in the regular-season finale.

Billed as a matchup between quarterbacks — long-time great Brady and second-year star Luck — the Patriots’ leader was content to hand off while Luck threw an interception on his second pass and never found consistency. He threw two touchdown passes to LaVon Brazill but also threw four interceptions.

Luck had three interceptions a week earlier but led the Colts from a 38-10 deficit early in the third quarter to a 45-44 win over the Kansas City Chiefs in a wild-card game.

"We had our chances, man, to make plays and get our offense back on the field," Colts safety Antoine Bethea said. "Last game, we were able to do that, but it was a great quarterback, a great offense and a great team we were facing (Saturday)."

The Colts trailed 21-12 at halftime, then cut the deficit to 29-22 on a 35-yard pass to Brazill with 5:01 left in the third. The Patriots dominated the rest of the way.

"We just had to keep our foot on the gas pedal," Blount said, "and make sure that they didn’t to us what they did to Kansas City."

Blount’s first touchdown came on New England’s first offensive play after Alfonzo Dennard’s interception. He scored again on the Patriots’ second series.

Luck responded with a 38-yard touchdown pass to Brazill. Former Patriot Adam Vinatieri set an NFL record with his 59th post-season extra point, making it 14-7.

Blount’s third touchdown came 4:06 into in the second quarter before Vinatieri’s 36-yard field goal made it 21-10.

The Colts got a break late in the first half when Danny Aiken’s snap sailed over punter Ryan Allen’s head, ending up in a safety. The Patriots also got a break that the Colts didn’t get a touchdown out of it after Allen failed to concede the safety.

Allen fumbled into the air and Indianapolis’ Jeris Pendleton slapped the ball out of the end zone.

"Ryan probably wasn’t sure how close they were to him," Belichick said.

Allen hurt his shoulder on the play and placekicker Stephen Gostkowski punted the rest of the game. Brady took over Allen’s holding duties.

Indianapolis got the ball on the free kick, but the drive ended with Luck’s second interception.

Vinatieri’s 21-yard field goal early in the third quarter made it 21-15.

Then the Patriots took a 29-15 lead on Ridley’s 3-yard run and his carry for a 2-point conversion.

But Luck came right back with his second touchdown pass to Brazill.

"We didn’t accomplish the ultimate goal," Colts running back Donald Brown said, "but there are definitely some positives to look back on."

Brady completed 13 of 25 passes for 198 yards with no touchdowns or interceptions. Luck was 20 for 41 for 331 yards.

Notes: Former NBA star Charles Barkley was in the Patriots’ locker room after the game. "I’m a big fan of his," Belichick said. … A moment of silence was held for 17-year-old Sam Berns of Foxborough, whose battle with a rare and fatal genetic condition that accelerates the aging process inspired Patriots players and was the subject of an HBO documentary "Life According to Sam." He died Friday. He had been invited by Patriots owner Robert Kraft to be the team’s honorary captain Saturday.