Royal Challengers Bangalore claimed a 13-run win over Chennai Super Kings to boost their playoff hopes and leave those of the defending Indian Premier League champions hanging by a thread.

CSK had got back to winning ways on Sunday in their first game since MS Dhoni returned as captain, but this time they fell victim to the bowling efforts of Harshal Patel (3-35).

RCB, who had lost three on the spin, were restricted to 173-8 with the bat, but that tally proved beyond CSK despite Devon Conway's second successive half-century.

It means RCB move back into the top four with 12 points with three games to go. CSK have a game more to play but are six points further back in second bottom.

Moeen Ali was excellent with the ball for the Super Kings and stunted RCB's early progress by ending the 62-run opening stand between Faf du Plessis (38) and Virat Kohli (30).

Du Plessis was caught at deep midwicket by Ravindra Jadeja off Moeen who, after Glenn Maxwell was run out, then bowled Kohli through the gate, leaving the former India captain shaking his head and RCB on 79-3.

But Mahipal Lomror (42) rebuilt RCB's innings through partnerships of 44 with Rajat Patidar (21) and 32 with Dinesh Karthik (26 not out).

CSK's once-promising chase lost impetus that primarily came from Conway's 37-ball stay.

He hit six fours and a pair of maximums before picking out deep backward square leg at the start of the 15th over. The impressive Harshal dismissed Jadeja for just three before claiming the key wicket of Moeen (34), who was undone by the slower ball one delivery after hitting his second six.

Dhoni (2) misjudged a pull shot from Josh Hazlewood as CSK lost their seventh wicket, Dwaine Pretorius (13) left with too much to do as his exit at the hands of Harshal effectively ended the contest.

Moeen continues Kohli hoodoo

Kohli has fallen to Moeen 10 times in international cricket and the spinner again worked his magic against the India great in the IPL with a superb delivery outside off that turned past the inside edge and clattered into the stumps.

Fifth title a long shot for CSK

Last season's crown marked the fourth in IPL history for the Super Kings but their hopes of equalling Mumbai Indians' record of five look to be all but over after they let some promising positions slip against RCB.