Paul Konerko hit grand slam to lift the Chicago White Sox past the Boston Red Sox 8-2 on Thursday night.

Konerko’s 39th homer broke open a 2-2 tie in the fourth inning. John Danks (15-11) got the win pitching six innings, allowing five hits and two runs while striking out six.

Boston starter Jon Lester (19-9) failed in his attempt to win his 20th game of the season for the first time in his career. Lester, who had won six straight starts, was hit hard in allowing nine hits and eight runs in just four innings. He also walked five and struck out five.

Victor Martinez hit a two-run homer to give Boston a short-lived 2-1 lead in the third inning.

Dayan Viciedo cracked a two-run homer for Chicago sending Lester to the showers.

The game was delayed 21 minutes by a power outage in the sixth inning.