From leading the table with four wins on the trot, the Virat Kohli-led team has slipped to third spot at the halfway stage after suffering two defeats from their last three matches.
Punjab made a winning start but then slumped to three straight losses before producing a clinical show to beat defending champions Mumbai by nine wickets on Friday.
Often known as slow starters, MI lost the other day due to the individual brilliance of RCB's Harshal Patel and AB de Villiers on a two-paced wicket here.