New England running back LeGarrette Blount (29) heads down field for a 73-yard touchdown run during the second half. He finished with 166 yards rushing and scored four touchdowns as the Patriots moved on the AFC title game. (Matt Slocum/AP)

There was a pinhole of light, then a crack in the door, then nothing but green turf through the raindrops. LeGarrette Blount hasn’t been a mainstay for the New England Patriots machine, and in fact he was acquired in a throwaway trade less than nine months ago. But here he was Saturday night, running free at Gillette Stadium, dragging the Patriots into another AFC Championship Game with four — count ’em, four — touchdowns in a 43-22 victory over the Indianapolis Colts.

The clincher was a 73-yarder early in the fourth quarter, one that opened a two-touchdown lead that proved too much for Colts quarterback Andrew Luck to overcome. It developed quickly, over right tackle, and when no one in the secondary slid to fill the hole, Blount — acquired for backup running back Jeff Demps and a seventh-round draft pick in an April trade with Tampa Bay — finished it off.

Blount’s performance — 24 carries for 166 yards and those four scores — means the Patriots will play in the conference title game for the third straight year, at Denver should the Broncos beat San Diego on Sunday, or right here should the Chargers pull an upset. But it also highlighted a New England team that may be transforming just as the postseason gets rolling.

“They gave me a chance to run it as much as I wanted to, as much as I could handle,” Blount said.

New England’s other two touchdowns came on runs from Stevan Ridley. Quarterback Tom Brady, who Saturday night became the only player in NFL history with more than 6,000 postseason passing yards, was in the odd position of being an afterthought. Couple this game, in which New England gained 234 of its 419 yards on the ground, with a 267-yard rushing performance in the regular-season finale against Buffalo, and it’s possible the Patriots’ days of slinging the ball around are over — or at least temporarily on hold.

That would play well around here, where the Patriots have recently been cause for as much frustration as celebration. For all the success this region’s pro sports have enjoyed over the last decade — success that has both fatigued and nauseated other parts of the country — there is some angst around this franchise, which began the entire run with the first of three Super Bowl titles following the 2001 season. Since the last Patriots’ victory, though, the Red Sox, Bruins and Celtics have all won championships.

So the pregame chatter among radio callers — enduring a day-long wait in the rain — consisted of breakdowns of Coach Bill Belichick as a talent evaluator and Brady as a big-game quarterback. The pair were, after all, just 3-5 in postseason games dating back to a freakish loss to the New York Giants in Super Bowl XLII.

But the fact of the matter is that whoever Brady has around him, whoever Belichick employs on either side of the ball, has helped push the Patriots to where they were Saturday night — hosting a playoff game for the 14th time. Before the pair arrived here, the franchise had all of four home playoff games — total.

And Saturday showed the kind of ingenuity that makes that kind of consistency possible. Yes, the Patriots benefited from Luck’s first error — a poor third-down throw to LaVon Brazill, one Alfonzo Dennard picked off and returned to the Indianapolis 2. Thus, Blount’s first postseason touch became his first postseason touchdown.

But Blount’s opening run was clearly part of an over-arching strategy for the Patriots. Blount, Ridley and Shane Vereen all carried the ball at least five times before halftime. Indeed, the Patriots ran 15 first-down plays in the first half — 12 runs and just three passes. The commitment was obvious, and when Blount scored from two yards out midway through the first quarter, the Patriots led 14-0.

“He’s been running that way all year,” Belichick said.

Luck, who engineered a remarkable comeback from a 28-point deficit against Kansas City in the wild-card round, immediately shot back with a stunningly athletic and accurate throw to Brazill for a 38-yard touchdown pass, and a shootout seemed afoot in the slop.

The Patriots easily could have come undone when long snapper Danny Aiken — you’re reading his name, so the result can’t be positive — sailed a snap over the head of punter Ryan Allen. The resulting mayhem turned into a safety for the Colts, a shoulder injury for Allen, the prospect of place kicker Stephen Gostkowski handling the Patriots’ punting duties, and Brady left as the holder for extra points.

Yet because the Patriots could get what they needed by simply running the football, none of that mattered. Luck threw three interceptions, but he was more than occasionally brilliant — never more so than when he covered 81 yards in two plays, the latter a 35-yard touchdown pass to Brazill that pulled the Colts within 29-22.

But when Blount took a handoff from Brady less than two minutes into the fourth quarter, that was about it. In his first 14 games for the Patriots, Blount never gained more than 65 yards and ran for three scores. In his last two games, he has 355 yards and six touchdowns. And at the most important time of the year, he might be reshaping the Patriots before our eyes.