The Blackhawks and St. Louis Blues were in their usual tussle heading into the third period. It was feisty and, on the scoreboard, it was tight. But when the third period began, the Blackhawks quickly ended the Blues’ night. Patrick Kane scored twice and Kris Versteeg had the game-winning goal and an assist as the Blackhawks beat the Blues, 4-1, Wednesday night at the United Center. The Blackhawks, who went 5-1-0 on the Circus Trip that wrapped up over the weekend, have now won seven of their last eight. With Corey Crawford out two to three weeks with a left-leg injury, Antti Raanta made his first start since Oct. 25. He shook off initial rust and stopped 40 of 41 shots. Marcus Kruger scored his fourth goal of the season. The Blackhawks gained plenty on that trip. They got cohesiveness among their lines. They got goals. They got victories. They got momentum. Sometimes those things can disappear when a team returns home, but that didn’t happen on Wednesday. The penalty kill paced them early, and their offense, fueled by the Versteeg-Brad-Richards-Kane trio, finished it off. The Blackhawks scored three times in the opening five minutes and 19 seconds of the third. “That was a great third period for us,” coach Joel Quenneville said. “That line scored some big goals over that trip and a couple big ones tonight as well. We had some penalty issues tonight, so commend our penalty killers and Antti as well. They kept us in the game. Tonight, we kind of played the way we did for most of the trip.” Indeed it was the penalty kill early. The Blues had six power plays, including five through the first two periods. The Blackhawks, sporting the NHL’s No. 1 kill, shut down a Blues power play that was fifth in the league entering Wednesday night.