So far, so good for Anthony ­Rizzo's debut week with the Cubs. With his first home run as a Cub on Saturday, the touted rookie got his second game-winning hit of the week in a 3-2 victory against the Houston Astros. "It just feels good to get that win and get that monkey off my back to get that [first] homer,'' he said. It was his second career homer — his first was last season in his short stay with the San Diego Padres — and the big blow in a three-run fifth inning against J.A. Happ (6-8) that assured Matt Garza (4-6) the victory. "He's doing his thing, so let him enjoy it,'' Garza said of Rizzo. "But this was a great team effort.''