WASHINGTON With a heavy road schedule to begin the season, the Giants knew April would be asurvival month. They had no idea how right they were. Already set back by injuries to Cody Ross, Andres Torres andMark DeRosa, the defending champs took their biggest hit yetSaturday, when they learned prior to a 2-1 victory at NationalsPark that Pablo Sandoval their fitter, resurgent Kung Fu Pandawould be lost for four to six weeks because of impending surgery torepair a fractured hamate bone in his right hand. Perhaps that news contributed to what Manager Bruce Bochy termeda team-wide fog, which included five impossibly wild innings fromJonathan Sanchez. But in the end, the Giants did what they must.