Hafner, scratched from the lineup because of a sore elbow, matched Al Rosen's 1951 club mark with his fourth grand slam of the season. The fifth-inning shot off Joe Mays (0-1) was salve for a team aching from back-to-back meltdowns in the ninth inning.
Left-hander Cliff Lee (8-5) remained unbeaten since May 29 and perfect during interleague play throughout his career. Lee gave up four runs in six innings, including Ken Griffey Jr.'s solo homer, while improving to 7-0 in 10 interleague starts.
A Cleveland bullpen that was rocked for nine runs in the series opener had plenty of margin for error, and needed it. Austin Kearns hit a two-run homer off reliever Rafael Perez in the seventh, and Ryan Freel homered off Fernando Cabrera in the eighth.
This time, there was too much ground for the high-powered Reds to make up.