BOSTON — They weren’t supposed to be here, these plucky and persistent Providence Friars.

And yet, on college hockey’s biggest stage, led by stalwart goalie Jon Gillies of South Portland, they not only proved they belonged — they stole the show.

Behind a superhuman, 49-save effort from Gillies that included a Superman leap across the crease in the final minute of play to knock down what appeared to be a sure goal, the Friars — the last at-large team selected for the NCAA Tournament, defeated the heavily favored Boston University Terriers on Saturday, 4-3, in the national championship game.

Gillies, a junior whose NHL draft right belong to the Calgary Flames, was also named tourney MVP.

The happy ending to the Friars’ season capped a tense playoff run that was nearly over before it began.

Providence was ranked among the top teams in the country to begin the season, and played like it at times, but the weekly grind of being student athletes inevitably caused baubles.

The Friars went 13-8-1 in Hockey East. Following a loss and a win against Boston University in their first Hockey East games of the season, Providence was just 2-3-2. Those were the only games the two NCAA finalists played against one another prior to Saturday’s meeting.

A mediocre beginning gave way to a solid stretch as fall morphed into winter. From Nov. 22 to Jan. 9, the Friars went 10-1.

Any swagger they gained there turned into a limping gait to the finish. Providence won seven of its final 13 regular-season games, leaving the squad on a precarious tourney bubble thinned to near nonexistence by a loss to the University of New Hampshire in the Hockey East quarterfinals.

If any team in any conference — including Hockey East — ranked outside the country’s top 15 teams won its conference tournament, the Friars were done.

So, they waited.

Minnesota State? Check. Miami? Check. Boston University, Harvard and Minnesota? (Each of those was instrumental.) Check, check and check. The three next teams looking for a berth, all of which were left out, were UMass-Lowell, which lost to BU in the Hockey East final, Colgate, which lost to Harvard in the ECAC final, and Michigan, which lost to Minnesota in the Big 10 final.

With a virtual homestand as the No. 4 seed in the East Regional, the Friars found their footing, dispatching Miami (7-5) and Denver (4-1). They kept rolling in another game within shouting distance of home, handling Omaha — Providence’s third consecutive opponent from the NCHC — in the national semifinal Thursday in Boston.

A seeing-eye shot from Ahti Oksanen snuck through a puck-sized hole between Gillies and the left post to give BU its first goal. Four seconds later, Danny O’Regan wrestled a backhand past a stunned Gillies after overpowering a defender.

Gillies and the Friars could have folded.

They didn’t.

Gillies persevered — a trait borne of being from a family of goalies, and of being raised among the hard-working people of Maine. The Friars took a cue from their keeper.

The teams traded second-period goals, but the Friars found a second gear in the locker room between frames.

A third-period gaffe by BU keeper Matt O’Connor and a snipe from forward Brandon Tanev flipped the script, rewriting an improbable ending to a dream season.

The Friars were one goal away from being eliminated from tourney consideration on the final weekend of conference play.

By one goal Saturday, they were national champions.