FOXBOROUGH — It’s a generally accepted sporting tenet that heroes are born in the fourth quarter, when lights shine brighter and hearts seem to pulsate at double their normal speed.

However, it was a pair of first quarters that proved the difference in the NCAA lacrosse semifinals on Saturday afternoon at Gillette Stadium, proving hot starts beget success as much as strong finishes.

In the opener, third-seeded Yale reached its first national championship game in program history with a 20-11 win over No. 2 University at Albany, greeting the Great Danes with a seven-goal barrage in the opening 10:26 before Albany managed to break the ice. Fourth-seeded Duke followed, stunning top-ranked Maryland with an impeccable 4-0 first quarter en route to a 13-8 victory over the defending champion Terrapins.

Yale (16-3) and Duke (16-3) will reconvene at Gillette on Monday at 1 for the national championship.

Perhaps the most stunning element of Saturday’s proceedings was a Maryland attack that lacked the punch and verve its fans have grown accustomed to. The Terrapins were held to a single-digit goal total for just the second time this season, the first coming on April 28 in an 8-7 triple-overtime win over Johns Hopkins.

Celebrating his birthday, freshman midfielder Nakeie Montgomery energized the Blue Devils with an ice-breaker less than 90 seconds into the first quarter. Montgomery finished with three goals, bringing his tournament total to eight after recording only six through 16 regular-season contests. Fellow freshman Joe Robertson recorded a hat trick of his own.

“Coach always says that at this time of year, the freshmen aren’t freshmen anymore, and you can really see that the way they’re playing,’’ said Duke senior attacker Justin Guterding, who added three goals and three assists. “Nakeie and Joe offensively have done an incredible job. Those guys are really coming into their role and starting to play like Duke men.’’

Foxborough native Sean Lowrie followed Montgomery’s first score with his own low snipe at 8:35 for a 2-0 Blue Devil advantage. The Blue Devils outshot Maryland, 12-5, in the opening frame, forcing the Terrapins out of their preferred deliberate pace and into transition whenever possible.

“Very proud of our guys for executing really well offensively early on, withstanding the run that you knew that Maryland was going to make, and then again executing really well and with a lot of contributions from a lot of people,’’ said Duke coach John Danowski. “I thought it was a real team effort, and we’re delighted to be together for another two days.’’

Maryland (14-4) came out firing in the third quarter, cutting Duke’s lead to one on a Bubba Fairman laser at 8:05. It was the closest the defending champions would get.

“They started out fast, and we certainly did not,’’ said Maryland coach John Tillman. “We just had a tough time getting our feet under us early, and they made us pay.’’

Playing in its first Championship Weekend since 1990, Yale operated with vengeance from the opening faceoff, balancing a poised but potent attack with a hounding defense befitting the heightened stage.

Senior attacker Ben Reeves proved a nightmare matchup for Albany (16-3), dicing up the Great Dane ranks in a scorching performance that featured five goals and four assists. Sophomore Matt Gaudet (six goals) was equally stellar, scoring goals on his first five shots in the first half.

“I think from Day One when I got to school, Ben was really very welcoming,’’ said Gaudet. “I think he saw a little bit of a future in me, so he trusted me a lot along with Jackson [Morrill]. From Day One, we’ve just built this chemistry where it’s like, I’m going to trust you to do your thing, whereas [Ben and Jackson] draw a lot of attention and my goal is to be a finisher. I think it works pretty well together.’’

With 4:34 remaining in the first quarter and a 6-0 Yale advantage, Bulldog sophomore attacker Jackson Morrill (three goals, five assists) found Reeves from behind the net, the senior lowering his release point waist-high and firing the ball off the bottom of Albany goalie J.D. Colarusso’s stick, through his five-hole. The snipe prompted Albany coach Scott Marr to temporarily yank Colarusso, an All-American, who had failed to stop the first seven Yale attempts from finding the back of the net.

“Not everything that J.D. is doing in there is his fault,’’ said Marr. “Some of those shots were right on top of him. But we thought about taking him out and giving him a little bit of a break to maybe just get his head together a little bit for a couple minutes.’’

The final sequence of the first half was indicative of Yale’s utter dominance. After Marr called a timeout to set his defense with less than five seconds remaining, Reeves bolted off the referee’s whistle from behind the net, finding a cutting Morrill who converted past the reinserted Colarusso with a second remaining for a 12-5 halftime advantage.

Senior attacker Connor Fields led the Great Danes in their first NCAA tournament semifinal appearance with three goals and two assists.