Jaylen Brown scored 17 points to lead six Boston scorers in double figures as the visiting Celtics routed the Miami Heat 95-78 on Thursday, using an impressive defensive effort to snap the Heat’s five-game winning streak. Dennis Schroder scored 14 points, Aaron Nesmith had 13 and Romeo Langford chipped in 12 for Boston, which won its second straight following a three-game losing streak. Al Horford and Jayson Tatum had 10 points apiece for the Celtics, whose four wins have all come on the road. Miami, which entered the contest averaging a league-high 115.6 points, recorded a season-low point total and shot 34.6 percent from the field and 9 of 41 (22 percent) from 3-point range. Kyle Lowry had six points, seven rebounds, and five assists for Miami before leaving at the end of the third quarter due to a sprained left ankle. Jimmy Butler scored 20 points, Duncan Robinson had …