BOSTON — Kyle Schwarber hit Boston’s third grand slam in two games, a drive off José Urquidy in a six-run second, and the Red Sox took a 9-0 lead after three innings against the Houston Astros in Game 3 of the AL Championship Series on Monday night.

Boston, seeking to take a 2-1 lead in the best-of-seven series, joined the 1998 Atlanta Braves as the only teams with three slams in a postseason — and the first with three in a series.