India: Mumbai Indians won the IPL final on the very last ball for a sensational one-run victory against Chennai Super Kings on Sunday.

Shane Watson's 80 off 59 balls nearly took MS Dhoni's team home, but the Australian allrounder was run out in the last over as Mumbai restricted Chennai to 148-7 and clinched its fourth Indian Premier League title.

Earlier, after winning the toss and electing to bat first, Kieron Pollard's unbeaten 41 off 25 deliveries had lifted Mumbai to 149-8.

Mumbai won both its league matches against Chennai this season and also won the Qualifier 1 against Dhoni's side before making it 4-0 on Sunday.

‘As a captain, I am learning with every game and every tournament, but need to give credit to the team,’ Mumbai skipper Rohit Sharma said.

‘I thought we could use Hardik (Pandya) for the 20th (over), but wanted to back someone who has done it for us. (Lasith) Malinga has done it many times in the past, so not a very difficult decision.’

Watson's belligerent knock, which featured eight fours and four sixes, left Chennai needing nine runs off Malinga's last over.

However, Watson attempted to retain the strike off the fourth delivery and got run out and Thakur was trapped leg before wicket off Malinga's last delivery.

‘Today was one game we should've done slightly better,’ Dhoni said.

‘It was quite a funny game, we were passing the trophy to each other. Both (teams) committed mistakes, and eventually the winning team was the one that committed one mistake less.’

Watson, who was dropped three times during his knock, and Dwayne Bravo brought the target down to 42 off the final four overs when they smashed 20 runs off Malinga's 16th over.

Jasprit Bumrah (2-14) bowled two impressive overs and also had Bravo caught behind.

‘We know finals can be close, so wanted to stay calm. Winning fourth title for Mumbai makes me very happy,’ Bumrah said after receiving his man of the match award.

‘Today I was surprisingly very calm ... (and) backed my skills.’

Inbetween those two Bumrah overs, Watson kept Chennai in the hunt by lofting left arm spinner Krunal Pandya for three successive sixes in the 18th over before Malinga returned and quashed Chennai's hopes.

Quinton de Kock (29) had earlier provided a brisk start before Mumbai lost both de Kock and captain Rohit Sharma at the same total of 45.

Seamer Deepak Chahar (3-26), who had Sharma caught behind, returned and claimed the wickets of Hardik Pandya (16) and Rahul Chahar (0) in the 19th over.

But Pollard ensured Mumbai had enough runs on the board to defend by clubbing three sixes and three fours in his unbeaten knock.