Requiring 16 off the final over, Mohit Sharma was clobbered for a six on the second ball before the Haryana medium pacer pulled things back to bowl three consecutive dots as Mumbai ended on 223/6 at the end. Earlier, it was stumper Wriddhiman Saha's 55-ball unbeaten 93 that propelled the visitors to the highest total this season.
With the win, Kings XI retained their fifth spot in the IPL standings, with seven wins from 13 games and now need to win their final league clash against third-placed Rising Pune Supergiant on Sunday to make it to the top four.
Chasing a mammoth 231, Mumbai, who have already qualified for the play-offs, looked on course with the opening duo of Lendl Simmons (59 off 32 balls) and Parthiv Patel (38 off 23) putting on 99 runs before losing four wickets for 22 runs to fall apart.
A late surge by Hardik Pandya (30 from 13) and Keiron Pollard (50 not out off 24), including a 27-run 16th over from Matt Henry, failed to take the home side as Punjab tightened the noose towards the end.
Mumbai got off to a flier with Simmons and Patel clobbering the bowlers all over the park, to race to 52/0 in just five overs. Simmons was at his brutal best, welcoming Mohit Sharma with two sixes before taking left-arm spinner Axar Patel to the cleaners twice in the next over to bring up his half century off just 27 balls.
Parthiv, who till now was playing second fiddle to Simmons, punished Mohit for three consecutive boundaries before falling on the fourth ball of the over. The Gujarat southpaw skewed a short ball straight in the air for Manan Vohra to latch on to a comfortable catch running across from cover to mid-off.
Simmons, who survived a dropped chance on 44, when Mohit failed to latch on to a regulation catch, failed to carry on the good work and was undone by a one-handed stunning catch by Martin Guptill at the long-on boundary off Punjab skipper Glenn Maxwell. The West Indian struck five boundaries and four massive sixes.
Leg spinner Rahul Tewatia then jolted the hosts with the wicket of skipper Rohit Sharma (5) before Axar Patel struck with the wicket of Nitish Rana for a run-a-ball 12.
Struggling at 121/4, Mumbai's hopes depended on the big-hitting duo of Keiron Pollard and Hardik Pandya, who added 55 runs for the fifth wicket and frustrated the Punjab bowlers with their power shots.
Hardik out-scored Pollard at one point, clobbering Tewatia for a six before milking Henry for two consecutive maximums before a sensational diving catch from Saha off Sandeep Sharma proved fatal for the all-rounder.
Leg-spinner Karn Sharma (19 off 6) used the long handle to good effect, adding 31 for the sixth wicket with Pollard as Mumbai crossed the 200-run mark before Mohit's slower delivery saw the southpaw's off-stump flying.
Earlier, Saha's excellent effort laced with 11 boundaries and three sixes, helped the Kings to their third highest IPL total after being put in to bat.
Kings XI were off to a flying start with the new opening duo of Martin Guptill (36 from 18 balls) and Saha putting on 68 runs before being separated by Karn.
Saha, who was promoted to open the innings after South African Hashim Amla left to join his national side for the upcoming ICC Champions Trophy, complimented the New Zealand big hitter well as the Punjab side raced to 50 off just 24 balls.
Joined by captain Glenn Maxwell (47 off 21), the second wicket partnership flourished to 63 in no time as the Australian meted out special treatment to Karn and veteran offie Harbhajan Singh, clobbering the spinners for five sixes in consecutive overs.
Comfortably placed at 131/2, Aussie Shaun Marsh (25 off 16) got down to business immediately, clobbering Harbhajan and McClenaghan for two sixes to add 52 runs for the third wicket with Saha, who by now had reached his half century off 31 balls as Punjab raced to 183 in 17 overs.
Mumbai managed to pull back things for a while but could not stop the visitors cross the 200-run mark as the left-right combo of all-rounder Axar Patel (19 not out of 13) and Saha added an unbeaten 47 for the fourth wicket to power the side to the massive score.
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