In-form Glenn Maxwell has gone for broke again in the Indian Premier League - but, this time, the gamble didn't pay off.

The Australian allrounder, looking to lead Royal Challengers Bangalore's tough chase against Kolkata Knight Riders in Bengaluru on Wednesday, fell early as he went for a heave-ho, leaving all the onus on teammate Virat Kohli to work his wonders.

But after making yet another IPL fifty, the great Indian batter fell for 54 off 37 balls and, for once, RCB's 'big three' - Faf du Plessis, Kohli and Maxwell - who went into the match having scored nearly 79 per cent of all of the team's runs, failed to get them across the line.

They eventually fell to a 21-run defeat, with the Knight Riders delighted to have prevailed in a 'must-win' game to keep their top-four hopes alive.

Player of the match was KKR's mystery spinner Varun Chakravarthy, who was responsible for getting rid of Maxwell for just five off four balls.

Trying to muscle Varun over the mid-off, Maxwell got a bit cramped and only managed to deposit his shot straight into the arms of David Wiese, leaving the Aussie to lean over his bat, head bowed, contemplating his early departure.

Varun (3-27) and Suyash Sharma (2-30) combined for five wickets, as Bangalore ended on 8-179 in response to KKR's 5-200, the centrepiece of which was rejuvenated Jason Roy's 56 off 29 balls at the top of the order. Skipper Nitish Rana also hit 48.

Roy, looking in the sort of mood to re-establish his credentials as one of England's white-ball powerhouses, smashed four fours and five sixes in bringing up his second straight IPL half-century off 22 balls.

For Bangalore, du Plessis, the league's leading scorer with 422 runs, still wasn't fit enough to lead the side, with Kohli taking the reins. The South African was used instead as the impact sub, but made only 17.

Kohli, though, got his fifth half-century of the season and is now the second-top scorer, but he couldn't build any partnerships as RCB suffered their third home loss of the season.