Pietersen smashed seven fours and a six in his rapid-fire 66 off just 44 balls. Robin Uthappa (22 off 8 balls) changed the course of the match when he smashed two sixes and a four off Brett Lee in the seventeenth over.
Bangalore lost Virat Kohli (42) after he added a valuable 76 runs with Pietersen to lead their run chase against Punjab.
Kohli slammed four boundaries and a six in his 26 balls cameo before Bipul Sharma dismissed him in the sixteenth over.
Chasing 182-run target, Bangalore lost Manish Pandey (29) and Jacques Kallis (9) early against Kings XI at PCA Stadium, Mohali.
Young Manish Pandey was going smoothly, hitting three fours in his 25-ball inning, before being run out unluckily in the seventh over.
Punjab pacer Shalabh Srivastava dismissed in-form Kallis with his very first ball of the match in the fifth over to give Punjab an early breakthrough.
Earlier, Kings XI batsmen clicked in unison to post 181/5 against Royal Challengers at PCA Stadium.
Ravi Bopara (42 not out) and Irfan Pathan (16) added a quick-fire 31 runs in the end of the innings to set a respectable 182-run target for Bangalore.
After losing skipper Kumar Sangakkara (45) and Manvinder Bisla (28) in quick succession, Yuvraj Singh (36) and Bopara added 65-run partnership to provide the platform required for a massive total.
Yuvraj slammed three fours and two sixes in his 20-ball cameo.
Sangakkara and Bisla also added a valuable 63-run partnership to lead the Punjab run charge after losing Marsh early. Sangakkara smashed eight fours in his 27-ball 45 blitzkrieg, whereas Bisla hit four boundaries in his 26 balls inning.
Kings XI lost opener Shaun Marsh (2) when Vinay Kumar dismissed the batsman in the second over to give Bangalore an early breakthrough in the match.
