Joe Mather singled in the go-ahead score in a three-run eighth inning as the Cubs rallied for a 5-3 win over the Rockies.  Brett Jackson tied the game with a solo homer and a throwing error plated an insurance run for Chicago, which took the opener of the three-game set at Wrigley Field.  Alfonso Soriano also homered as the Cubs snaped a four-game skid.  James Russell got the win in relief and Carlos Marmol posted his 16th save.  Matt Belisle [[ buh-LYLE ]] took the loss.  Chris Nelson and Carlos Gonzalez homered for Colorado, which had won five straight.