Three times the Portland Pirates have stepped onto the ice knowing a loss would mean the end of their season.

Now the Manchester Monarchs, the team with the best record in the American Hockey League, get a chance to walk that same tightrope.

The Pirates, the last of 16 AHL teams to qualify for the Calder Cup playoffs, have pushed Manchester to the brink of elimination by winning Games 3 and 4 at home to force a decisive Game 5 on Saturday night in New Hampshire.

“The pressure isn’t on us,” said Portland goaltender Louis Domingue, who made 28 saves in Thursday’s 5-0 shutout in Portland. “We’re playing loose. We’re doing the right things. You see the results.”

The Pirates made the playoffs by rallying from two down in the third period to win their season finale 5-4 in Worcester. After dropping the first two games of their Eastern Conference quarterfinal series in Manchester by a combined 11-4, the Pirates stayed alive with a 3-2 victory Sunday night in Portland when Francis Wathier scored in the waning seconds.

Then came Thursday night. The Pirates were outshot for a fourth straight game but again won, in large measure because they held the AHL’s top power-play unit without a goal in six opportunities.

“We didn’t capitalize on any chances on our special teams,” said Brian O’Neill, the Manchester right wing, and the league’s top scorer and MVP. “We’ve got to be better in Game 5. I think we will.”

The Monarchs are trying to avoid a fifth straight first-round playoff exit. Since joining the AHL in 2001, Manchester has been one-and-done 10 times in 12 playoff appearances.

That kind of history can weigh on a team come should a deciding game be close.

Which is why the Pirates must avoid stumbling out of the gate as in Game 1 (trailing 2-0 in the first four minutes) and Game 2 (trailing 2-0 in 30 seconds).

“It’s hard to play that team when you’re chasing them,” said Coach Ray Edwards. “The first 10 minutes is going to be real important. We’re going to have to have a real focus going down there and being ready to play.”

A key to the Pirates’ success has been penalty-killing. Manchester had the AHL’s best power play (20.7 percent) but has converted only 3 of 23 chances (13 percent) in the playoffs.

Nonetheless, the Pirates cannot continue to put themselves at a disadvantage (25 minor penalties in the series to 17 for Manchester). Heading into the weekend, no other AHL playoff team had been short-handed as many times as Portland’s 23.

“We took some bad penalties (Thursday) night,” Edwards said. “We can’t do that in Game 5. Those (penalty killers) have done a great job all year, but sooner or later you’re going to get bitten.”

A tight-checking, low-scoring game would suit Edwards. Thirty-five times this season the Pirates have mustered three goals in a game. When doing so, they have yet to lose in regulation.

Despite a raft of late-season injuries that sidelined Alexandre Bolduc, Jordan Martinook, Justin Hodgman, Evan Oberg and Darian Dziurzynski, the Pirates have tied this series by getting contributions from everywhere. Nine players have scored once and Wathier, after only five goals in the regular season and three in his first 56 Calder Cup playoff games, has become Superman.

He has three goals, including two winners, in the past two games. Until the injuries, Wathier’s role was limited. A valued veteran locker-room presence, he played conservatively on the ice.

“When you have a slowed-down role, you want to make sure you play the right way and you give momentum to your team,” he said. “Scoring is a bonus. But come playoff time, when Coach is giving you more opportunity, you want to be able to reward him and reward yourself. I want to stay in that role.”

Game 5 could be another Manchester blowout. Game 5 could be another tale in the growing Wathier legend. All those extra hours in the weight room, on the exercise bike, eating right, getting proper rest, are allowing a 30-year-old to beat a much younger defender to the net.

“It’s been fun,” Wathier said. “Hopefully we can keep it going.”