(CHICAGO) - The toughest part of having COVID-19 for Jayson Tatum wasn't the headache, the high temperature and chills he experienced. Most difficult was the mental toll. Tatum scored 24 points after missing five games, Jaylen Brown had 26 and the Boston Celtics beat the host Chicago Bulls 119-103 on Monday night. Tatum said he felt a bit tired in the first half. But he got a second wind. Daniel Theis scored 19 points and Marcus Smart added 13 while tying a career high with 11 assists as the Celtics won their second straight. Zach LaVine led Chicago with 30 points and shot 6 of 10 on 3s. But he also committed six turnovers, giving him 13 in the past two games. Lauri Markkanen scored 18 points and Thaddeus Young just missed a triple-double with 16 points, nine rebounds and nine assists, but the Bulls dropped their second in a row after three consecutive wins.