Delhi Capitals captain David Warner remains hopeful of a turnaround despite his team's fifth straight loss in the IPL after their 23-run defeat by Royal Challengers Bangalore on Saturday.

Virat Kohli struck 50 to guide hosts Bangalore to 174-6, a total their bowlers defended by restricting Delhi to 151-9 in the first match of the day.

Later, Zimbabwe all-rounder Sikandar Raza's 57 and an unbeaten cameo by Shahrukh Khan led Punjab Kings to a two-wicket win over Lucknow Super Giants as they entered the top four in the table.

"The positives were great... the bowling and the fielding were exceptional. I said that to the guys that their energy and attitude were absolutely amazing," Warner said after Delhi's loss.

"It's just our batting. We need to work out how to take on the powerplay and not lose early wickets."

Delhi were never in the chase, losing regular wickets.

Even Warner, who has scored 228 runs with three half-centuries in the tournament but has struggled with his strike rate, only scored 19.

Manish Pandey made 50, but the rest of the batting fell apart as debutant and local boy Vijaykumar Vyshak returned figures of 3-20 for RCB.

The returning Mitchell Marsh, back after getting married in Australia, struck first for Delhi with the wicket of Faf du Plessis and later dismissed Mahipal Lomror.

- Kohli makes another fifty -

Left-arm wrist-spinner Kuldeep Yadav also took two wickets, but Bangalore scored enough to claim a second victory in four matches.

Kohli posted his third fifty of the season before falling to Lalit Yadav in the 11th over.

Kohli smashed six fours and one six in his 34-ball knock.

Lucknow skipper KL Rahul anchored his team's innings of 159-8 against Punjab with 74.

But questions remained over Rahul's batting approach after his 56-ball stay.

Raza's maiden IPL half-century kept Punjab, captained by Sam Curran in the absence of the injured Shikhar Dhawan, on track in their chase before his departure in the 18th over.

The big-hitting Shahrukh then hit the winning runs in his 10-ball 23 as Punjab achieved their target with three balls to spare.

Curran, who became the most expensive IPL player in the auction, posted his best bowling figures of the tournament so far, taking 3-31.

"Raza played nicely in the middle, and the way Shahrukh came in and finished," said Curran.

"The word around the dressing room is that he (Shahrukh) has worked very hard and the coaching staff have been clear with his role."