Kevin Pietersen struck 26 not out to help his Delhi Daredevils pour more misery on defending champions Mumbai Indians, who lost for a fourth time in a row.
Pietersen ensured Delhi had no trouble reaching their poultry target of 126 against the reigning Indian Premier League kings, who remain rooted to the foot of the standings after a nightmare start.
The damage was done in the first half of the match as Mumbai failed to recover from 46-4 after winning the toss, posting just 125-6 in Sharjah.
Kieron Pollard top-scored from No 6 with 33 not out and left-arm medium-pacer Jaydev Unadkat (2-29) was the pick of the Delhi attack.
Murali Vijay led from the front in reply, posting a composed 40 off 34 balls to put the Daredevils well in touch with the required-rate.
Pietersen took six balls before making his move, launching opposite number Rohit Sharma for a huge six down the ground before following that blow up with back-to-back boundaries.
He allowed team-mate Kedar Jadhav the honour of sealing the win, a victory which keeps Delhi in sixth with two wins from five matches.