Hillgrove even pulled within 10 points with 2:20 to play when Henry passed 18 yards to Kenyan Drake. But McEachern had one final answer when Purnell ran 46 yards for the final score of the night with 1:11 remaining.
Hillgrove finished with a 607-508 advantage in total offense. Henry was 30-for-44 passing for 466 yards and five touchdowns and rushed for 66 yards on 12 carries. Jojo Marshall and Drake each finished with more than 100 yards receiving.
McEachern was led by Purnell, who was 12-for-16 passing for 252 yards and five touchdowns and had 101 yards and a touchdown rushing. Amba Etta-Tawo caught six passes for 156 yards and two touchdowns.
McEachern led 24-14 after two quarters in which the teams combined for 466 total yards. Okpala scored on a 1-yard run, Purnell had two touchdown passes and St. Germain kicked a 21-yard field goal. But Hillgrove had two touchdown passes from Henry to stay within 10 points.
Hillgrove opened in 2006 to relieve overcrowding in several west Cobb schools, particularly McEachern, about three miles away. The redistricting process was contentious, eventually reaching the courts and the Legislature, and both sides were left with hard feelings. But because Hillgrove played its first four seasons in Class AAAA, the schools had not met before Friday’s game.