Marlon Byrd's sac-fly capped a three-run eighth inning as the Cubs rallied for a 7-6 win over the Pirates. Carlos Pena tied the game when he drew a bases-loaded walk in the eighth. Blake DeWitt clubbed a two-run homer, while Pena and Geovany Soto added solo shots as the Cubs completed a four-game sweep. Chicago has won five in-a-row overall. Jeff Samardzija tossed a scoreless inning to get his sixth win. Carlos Marmol earned his 23rd save. The Northsiders return to Wrigley Field this afternoon for a three-game series against the Cincinnati Reds. Ryan Dempster gets the nod opposite Mike Leake in the opener.