The Astros hit five home runs in the second inning off Nathan Eovaldi of the Red Sox. Going back to 1974, I find three other instances of teams hitting five home runs in one inning. The last time it happened was on 9/17/2020 when the Yankees hit five at home against the Blue Jays, all off Chase Anderson.

The Astros lead the Red Sox 9-1 in the top of the third inning.