BOSTON -- Let's be honest: The Boston Bruins overachieved by earning a playoff berth.

And their issues with offensive and defensive depth, along with injuries to key players, have proven to be a thorn in the Bruins' side against the Ottawa Senators in the first round. The Bruins produced a dramatic double-overtime victory to stave off elimination in Game 5 and will attempt to extend the series when they host Game 6 on Sunday, 3 p.m. ET, at TD Garden. The Senators lead the series 3-2 partially based on their defensive system, which has thrown a wet blanket over the Bruins' offensive chances.

But there's more hockey left to play. Here is how the Bruins can force a Game 7.

Crease crook: Bruins goalie Tuukka Rask needs to steal the show. He helped the Bruins reach the Stanley Cup finals in 2013, but they lost to the Chicago Blackhawks as Corey Crawford proved to be the better goaltender. That's as close as Rask has come. But his strong performance this season is the main reason the Bruins made the playoffs -- and his heroics in Game 5 were beyond outstanding, unquestionably the best postseason performance of his career. He made timely saves and a total of 19 in the two overtime periods. He finally stole a game and will need to equal or better that in Game 6 to force a Game 7.

Crash and bash No. 65: Senators defenseman Erik Karlsson has been outstanding against the Bruins, proving why he's again a finalist for the Norris Trophy, which is given to the league's best defenseman. The Bruins did a better job in Game 5 of getting Karlsson off his game by not chasing him when he has the puck. Karlsson's speed is his biggest weapon. He creates time and space better than anyone, and he closes in on the puck in similar fashion. The best way to contain Karlsson? Try to limit that time and space by putting pucks behind him, getting on top of him fast, and finishing checks on him as often as possible. He's tough to hit, but the Bruins need to make him go 200 feet with the puck to tire him out, and hit him in the process. Even just bumping him can wear him out, as long as it's consistent. Also, the Bruins need to be patient and possess the puck in the offensive zone when Karlsson is on the ice. And they need to stay out of the box: Taking penalties means he handles the puck on the power play, and the more he handles the puck, the more rhythm he finds. If the Bruins let him play off turnovers and transition, he will slice them up.

Marchand must stand tall: The Bruins need Brad Marchand and Patrice Bergeron to play at the top of their games. Karlsson has done a terrific job keeping Bergeron's line at bay. In fact, Marchand has only one goal and one assist in this series; Bergeron has one goal and two assists. But during the regular season, Marchand had 39 goals and 85 points in 80 games. During Boston's 2011 Stanley Cup run, Marchand was a rookie and had 11 goals and eight assists for 19 points in 25 playoff games. However, he has only six goals in 45 playoff games since then. Marchand needs to find that next level and become an elite playoff performer. Playing an elimination game on home ice should help motivate him.