After the opening 20 minutes Tuesday night at Verizon Center, it looked as though the Washington Capitals would fall short in yet another game they had dubbed a test of their progress. But trailing the talented and tenacious Boston Bruins by three goals at the end of the first period, the Capitals refused to go quietly. During intermission, players said Coach Adam Oates, captain Alex Ovechkin and newcomer Aaron Volpatti were among those who stressed there were still 40 winnable minutes left in regulation. It was plenty of time for the Capitals to mount a comeback if they put their minds to it. Washington did precisely that, scoring three goals in the final two periods to force overtime. Thirty-seven seconds into the extra session, winger Eric Fehr raced up ice, split two Boston defenders and scored while falling down for the game-winner in the Capitals’ 4-3 triumph that featured contributions from some unusual suspects. “We didn’t give up at all today,” said Fehr, who recorded a team-high three points. “I think it says a lot about our character. This team believes in ourselves a lot more than we did at the beginning of the season. We’re a pretty confident bunch right now and we’re believing in the system and that’s why it doesn’t matter who’s on which line. We’re playing together as a team and that’s why we’re able to win today.” The Capitals viewed their first meeting with Boston since last year’s Eastern Conference quarterfinal playoff series as a measuring stick. They felt they had greatly improved in recent weeks and were eager to face a Bruins squad that won six of seven heading into the matchup. After the first period, the challenge looked like more than Washington could handle. Brad Marchand scored on a short-handed penalty shot just 6 minutes 29 seconds into the contest to give the Bruins a 1-0 lead. Zdeno Chara and Dougie Hamilton each added a goal in the final three minutes of the first period and Washington appeared ready to fall back into sole possession of last place in the Eastern Conference standings. “You start to think after the first period like that, same old song and dance that we’ve been in, and the guys, really we all turned it around,” said goaltender Braden Holtby, who made 30 saves but said he would have liked Hamilton’s goal back. “I think it’s probably just that everyone’s sick of being down like that.”