CHICAGO — For a moment, the Chicago Blackhawks found a crack in the Washington Capitals’ defense and broke the stalemate in what had been a dog of a game. But then the dam broke. The Capitals rattled off three unanswered goals in the second period and held on to win 4-2 on Sunday at the United Center. The Hawks came into the game riding their first two-game winning streak, and early in the second period things were looking up. For the fourth game in a row, the Hawks struck first: Philipp Kurashev scored the game’s opening goal with a tip-in from the doorstep. Seth Jones found him with a cross-…
