KKR today defeated MI by 32 runs to jump to the second spot in the standings with 19 points and virtually seal their place in the four-team play-offs.
"If we had lost this we would have been under pressure. Today's win will give us confidence," he said at the post-match press conference.
Gambhir also said that even though 140 was not enough, the middle-order did a good job in posting a decent target on the board.
"I don't think we had enough, but after losing two wickets early then 140 was a good total. If we win the next one we'll be in the top two," he added.
MI skipper Harbhajan Singh said they need to work on their starts ahead of the final game against Rajasthan Royals on Sunday.
"I don't think there was much fault in the wicket, I think we need to sort out our technique and how to bat in the first six overs," he said.
"We haven't been playing great cricket. Boys need to pick up their game."
Man-of-the-Match Sunil Narine, who returned with impressive figures of four for 15, said he was having a dream tournament.
"I'm having a dream at this moment, hard work is paying off. Hopefully it will continue," he said.
