Boston Celtics take 3-0 lead over Mavericks in NBA finals, powered by scoring from Tatum and Brown

​ The Boston Celtics took a commanding 3-0 series lead over the Mavericks following a 106-99 win in Game 3 of the NBA Finals in Dallas on Wednesday – and are now one victory from clinching an NBA record 18th championship. Read More Breaking News, Latest News and Videos | CNN