SALEM – The Marblehead hockey team had lost to Swampscott twice during the regular season, playing arguably two of its worst games in those losses. But when the chips were down on Tuesday at Rockett Arena, the Headers had their best hand at the perfect time.Actually, goaltender Aaron Reny had the best hand.The junior stopped 17 of 18 shots in the third period with Swampscott swarming all over the Header net and then watched as freshman Chris McLeod scored 4:51 into overtime to give Marblehead the 3-2 upset over the No. 5 Big Blue in the first round of the Division 3 North tournament.The No. 12 Headers (11-10-0) move on to the quarterfinal round on Friday (5:30) at Ryan Arena in Watertown against No. 13 Latin Academy, which ousted No. 4 Shawsheen, 4-3.”That was a great high school hockey game,” Marblehead coach Bob Jackson said. “It’s just a shame that these two teams had to play in the first round.”Reny became the story in the third period as he came up with two of the game’s biggest plays, stopping Swampscott snipers Danny Rakoc and A.J. Zarinsky, the second coming with 1:20 left in regulation, to keep Marblehead alive.”Aaron played the best game of his career (Tuesday). He was like the Rock of Gibraltar in that third period. He was terrific. And stopping three breakaways like that is unbelievable.”For Reny, it was a sweet reward after having allowed seven goals in two games with Swampscott this season.”I thought that if the game went to a shootout that we’d be in big trouble,” joked Reny. “They beat us two times in the regular season but this is when it counts the most.”The emotions were completely different just down the hall in the inner sanctum of Rockett as the Big Blue saw its first postseason trip in 10 years end quickly.”We knew coming in that it would be a tough game,” Big Blue coach Gino Faia said. “Reny came up big when he had to. We had our opportunities but it just didn’t go our way (Tuesday).”The Big Blue (12-5-4) entered the third trailing 2-1 after Ellery Smith had scored with 6:00 left in the second, but made it very clear early on that Marblehead was going to have to work for its first tourney win since 1993.Rakoc had a glorious chance just 50 seconds in when he broke in alone from 60 feet on Reny. The senior forward made a great move, but Reny managed to get his left pad on the shot to make the save.That would be just the start of Reny’s work in the third as Swampscott hemmed the Headers in for nearly six minutes, putting 10 shots on net over that span. But none of them made their way across the goal line.Several times in the third period, Reny had the Swampscott forwards looking towards the heavens for answers and a little bit of help.And with 2:26 left in regulation, Swampscott got that help from above. Keith Morgan picked up a puck in the right circle and fed Justin Massey for a bullet over Reny’s shoulder and under the crossbar to tie the game.”We didn’t think as coaches that the game was going to finish 2-1 and we told the kids that,” Jackson said. “And (Swampscott) came out flying but the kids hung in well.”Less than a minute after Massey tied the game, Zarinsky had a chance to win it but Reny again flashed the pads to keep the game tied into overtime.”We said to the guys between the third and overtime that this is what it’s all about,” Jackson said. “And to listen to the crowd and look at the atmosphere.”In the extra session, the Headers only got two shots off against Conor Barton, but that’s all it took to decide the outcome when McLeod’s shot from the right circle nipped inside the right post to end things.”Marblehead is an aggressive, physical team and we knew that they wouldn’t roll over,” Faia said.