The Springfield Thunderbirds needed a boost from their defensive unit. Throughout the Atlantic Division Final, they've lacked that elite play from their blue line in a series where they can use it, especially against a Wilkes-Barre Scranton Penguins team with great defense and better goaltending. 

They got it in Game Four with their backs to the wall and with the team on the brink. Yes, Game Four was defined by the disallowed goal in the first period that gave the Thunderbirds life. However, the defense needed to have a big game, and it delivered, giving the team hope for a series victory with Game Five around the corner.

In the playoffs, they don't ask how. That was certainly the case with Marc-Andre Gaudet's knuckling puck into the back of the net that gave the Thunderbirds a 2-0 lead and essentially was the decisive goal in the tight game. 

The shot from Gaudet wasn't impressive and not something to write home about. His play on the goal to put himself in a prime position was. Gaudet joined the forwards on the rush and helped bring the puck into the offensive zone. He found the open look in the slot and put the puck on the net. 

Gaudet, like the rest of the Thunderbird blue line, is eager to get on the scoresheet. In Game One, his goal was what the team needed. In a series where the offense is struggling and goals are hard to come by, the defensemen chipping in will go a long way. Gaudet is one of the defensemen who can make that impact. 

Georgi Romanov delivered his second shutout of the Calder Cup Playoffs, yet it felt like he didn't have a tough night in the net. He only faced 20 shots, and few of them came from the high-danger areas. 

It speaks to the job the defense has done. They clamped down and blanked a great Penguins offense. It was a credit to protecting the interior of the defensive zone and how the defense is coming into form. The Gaudet and Calle Rosen pair is the one the Thunderbirds rely on the most, for both great plays defensively and for their ability on the offensive end. Theo Lindstein and Adam Jiricek, meanwhile, are the younger blueliners developing into reliable options, and the two have formed a great pair to keep the unit intact. 

Game Four wasn't just a great showing from the defense either. The forwards also played a key role in setting the tone for the game and blanking the Penguins' offense. I loved how we checked. We checked a lot of pucks back. Our reload was really strong. We played to our identity for the full 60 minutes," head coach Steve Ott noted after Game Four. The Penguins couldn't get a lot of chances, and it's a credit to the Thunderbirds, who prevented them from generating much, if anything, in Game One. 

In the first three games of this series, the Thunderbirds never received a spark from their defense. Even with Rosen and Gaudet making plays at the point, the Thunderbirds didn't look like a team capable of changing that game with their defense.

Game Four proved that the unit is coming into form. Yes, Rosen and Gaudet have stepped up throughout the playoffs, with a combined four goals and seven assists. Now, the entire defense is stepping up with Lindstein moving the puck and Jiricek finding his footing in the AHL. 

Game Five is when all hands are on deck. There's a good chance the game is a goaltending duel between Sergei Murashov and Georgi Romanov. It's why that one goal from the defense might be the difference. The Thunderbirds are starting to find those goals. Now, the question is whether they can pull off the upset and overcome the odds with their blue line giving them an edge.