'TDN Rising Star' Guarana (Ghostzapper), already a two-time Grade I winner from only five career starts, will look to remain undefeated around one turn in Saturday's GI Madison S. at Keeneland. Accorded 'Rising Star' status after romping by better than 14 lengths through the local slop last April, the bay defeated GI Kentucky Oaks heroine Serengeti Empress (Alternation) by a half-dozen lengths in the GI Acorn S. last June and successfully stretched to two turns in the GI CCA Oaks at Saratoga the following month. She suffered her first loss...