The Blackhawks have gotten where they are this season by playing smart hockey and keeping mistakes to a minimum. Monday, those mistakes were prevalent. And the Los Angeles Kings were more than willing to take advantage of them. Michael Frolik scored twice in his move to the top line, but Dustin Brown scored the game-winner with 1:27 remaining in regulation as the Kings beat the Blackhawks 5-4 at the United Center. The Blackhawks maintain their three-point lead over Anaheim in the Western Conference, as the Ducks lost to the San Jose Sharks, 5-3. The Blackhawks, still without Marian Hossa and Patrick Sharp (both sidelined with shoulder injuries), were coming off a four-day break in the schedule. They looked solid in the first period when Frolik’s first goal since the Jan. 19 season opener, also against the Kings, gave the Blackhawks a 1-0 advantage. But it went awry after that. Poor play on out from goaltending hurt the Blackhawks, who never held their leads long after the one in the first period. “(With the Kings) getting shut out two games in a row, they were going to be hungry. We didn’t respond to the challenge that was there tonight,” coach Joel Quenneville said. “I was disappointed with how we played and what we gave them. We can’t be happy with what we gave them.”