 Complete the following phrase:  Brock Lesnar engaged in a feud against Big Show over the WWE Championship. The feud began on the May 1, 2003 episode of SmackDown!, where Lesnar cut an in-ring promo against Big Show, stating that he was a coward for defeating Rey Mysterio at Backlash. Big Show later appeared on the stage, where he challenged Lesnar into a WWE Championship match.ref nameSD51arefref nameSD51bref The following week on SmackDown!, it was announced that Big Show would face Lesnar for the WWE Championship at 