Karthik admitted to the Level 1 offence (Article 2.1.3) of showing dissent at an umpire's decision during the match at Ferozeshah Kotla Ground last evening.
For Level 1 breaches of the IPL Code of Conduct, the Match Referee's decision is final and binding.
In the 11th over of Mumbai Indians innings, Karthik missed the ball while he was looking to sweep Ravindra Jadeja. The ball hit the pads and he was given lbw.