Chasing 169 to win, Buttler dominated from the word go and continued his sensational form as he stayed unbeaten on 94 off just 53 deliveries.
This after he lost his opening partner D'Arcy Short early after Jasprit Bumrah removed him in the first over.
Captain Ajinkya Rahane and Buttler then put on a 95-run partnership for the second wicket with Rahane proving to be a calming influence for Rajasthan.
By the time he departed for a 36-ball 37 the job was more or less done for the visitors. Samson then joined Buttler and hit a couple of big ones, he wanted to finish things in style but was dismissed on 26 by Pandya.
Buttler then deposited the next ball into the stands as Rajasthan reached the target in just 18 overs.
Earlier, Evin Lewis smashed a 42-ball 60 and Hardik Pandya's cameo of 36 helped Mumbai Indians reach 168.
Lewis added 87 runs with fellow opener Suryakumar Yadav (38 off 31) who was also dropped on nine by the Royals fielders. Lewis hit four sixes and as many fours in his innings.
Jofra Archer produced excellent bowling performance to put the hosts under pressure. He conceded only 16 runs from his four overs and dismissed Lewis and Suryakumar and Rohit Sharma (0) in successive balls.
He used the bounce available in the pitch, hit the deck hard and bowled straight into the batsmen, hardly giving any room to open their arms.
The hosts were struggling badly at one stage, failing to capitalise a good start, but Pandya came up with his blistering knock just in time to propel them. He hit three fours and two sixes in his 21-ball knock.
Archer troubled Lewis with bounce and created a catching chance but Stuart Binny could not hold on to the ball, which went up miles in the air. The Caribbean was on five then.
Suryakumar, who was also dropped on nine by Gowtham, though had adjusted to the bounce and negotiated both spinners and pacers nicely, playing confident drives.
The fluffed chances allowed Mumbai Indians to come out of Power-play overs unscathed and with 51 runs on the board.
With no success coming, Ajinkya Rahane employed new bowlers -- Shreyas Gopal and Jaydev Unadkat -- to the job but Suryakumar continued to find odd boundary as he swung his arms, when room was there.
The wicket was such that the batsmen could not set the field on fire. The home openers batted smartly to work the ball around and kept the scoreboard moving. Till the eighth over, no six was hit.
A desperate Rahane brought back Archer and he not only provided the Royals the breakthrough by getting rid of Suryakumar but dealt a massive blow to the hosts by dismissing rival captain Rohit Sharma (0) in the next ball.
Lewis raised his fifty with a six off Gowtham and also launched Dhawal Kulkarni for a six but the paceman stopped him in his tracks soon.
First Published: May 14, 2018, 7:50 AM IST