He tops the bowling charts for the team having claimed 16 wickets so far, his best IPL tally. The leggie went on to bowl a sensational spell conceding just 18 runs in his full quota of overs.
However, Kolkata could manage only five runs from it as Punjab completed a 14-run win and kept their hopes alive in the tournament.
Chasing a fighting target of 169, Kolkata got off to the ideal start with openers Chris Lynn and Sunil Narine started to hit boundaries from the word go.
Lynn played a lone hand for KKR and none of his team- mates contributed substantially. Mohit followed that up with a economical over before Manish Pandey (18; 23b; 1x4, 0x6) and Lynn got out.
Narine and Lynn started the chase in right earnest adding 39 runs in four overs but Kings XI Punjab came in with a definite plan to stop the run riot.
KKR were 82 for 3 at the halfway stage, needing another 89 to win the match.
Gambhir's 18-ball vigil finally ended by Tewatia (2-18), who also snared Robin Uthappa (0) in the same over after Lynn reached another quick fifty.
Earlier, Hashim Amla played a brilliant knock to notch up his second century of the ongoing IPL and power Kings XI Punjab to a challenging 189 for three.
After posting 167/6 at the PCA Stadium, Punjab bowlers came to the party keeping Kolkata waiting for their playoffs berth as the hosts put up an authoritative win.
What's even more worrying for KXIP is that they lost the match despite scoring 189/3 giving the Gujarat Lions a decent target to chase.
Martin Guptill and Shaun Marsh perished in quick succession, and it was left to Saha and skipper Maxwell to start the fix work.
Narine got his ticket to open the KKR innings after Chris Lynn suffered an injury in their second match of the IPL against Mumbai Indians and what a revelation he been since - 196 runs in 12 runs.
Due to the fact that the third and fourth-placed teams are in a do-or-die situation from match one, it becomes really important to finish in the top two, because those two teams get is one more opportunity at making the final, and that is something that can not be taken lightly.
Yadav though had the last laugh as he dismissed Vohra in the fifth over with a short delivery.
Next over, Martin Guptill fell LBW to Narine as the batsman missed the delivery while trying to sweep over backward square leg and Kings XI were 41 for 2 then. Kings will have to get their bowling into order as they have been below par apart from the brilliance of Sandeep Sharma with the new ball.