Put in to bat first by Punjab, RCB posted an intimidating 205/2, powered by skipper Faf Du Plessis (88) and Virat Kohli (41).
If Plessis-Kohli laid the foundation, Karthik put the finishing touches with 32 off just 14 balls, which included three fours and three sixes.
In this match, Karthik maintained calculated aggression throughout his innings.
With his side reeling at 87-5 while chasing 170 runs, DK performed the rescue act with all-rounder Shahbaz Ahmed (45).
He had a 67-run stand that took RCB to a win. DK finished at 44* off 23, with seven fours and a six.
With his side struggling at 92/5 against DC, Karthik had a valuable stand of 97 runs with Shahbaz Ahmed taking RCB to 189/5.
Karthik ended with an explosive 66 off 34 balls, consisting of five fours and five towering sixes.
At 167/3 in the 19th over with Karthik and Du Plessis at the crease, things looked good for RCB.
Looking to make this outing in green jersey memorable, DK provided excellent acceleration to the innings in the last over.
He smashed Fazalhaq Farooqi for 6,6,6,4, which took his side to 192/3.
Karthik finished with 30* off 8, with a four and four sixes. SRH lost the match by 67 runs.
In the eliminator against LSG, Karthik shared 92 run stand from 41 balls with Rajat Patidar, who scored an unbeaten 112.
DK scored 37* off 23 with five fours and a six, taking RCB to 207/4.
LSG fell 14-runs short of the target and RCB progressed to Qualifier 2.