United, invading Rockemperor clash in Santa Anita’s Whittingham

A bicoastal showdown looms on Saturday at Santa Anita Park as Richard Mandella’s United (Four Star Graduate) and Chad Brown’s eastern-based Rockemperor head a field of seven 3-three-year-olds and up in the Grade 2, $200,000 Charles Whittingham Stakes at a mile and one quarter on turf.