Knight Riders had a good start with Butt scoring a fluent 44-ball 48 but struggled against the probing Delhi seamers in the middle overs before Hussey's late slurry ensured local outfit post modest 133/6.
And in came Akhtar and out he went to wreck Daredevils top-order in his fiery first spell. Laxmi Ratan Shukla (3/6) ran thro' the lower-order as Delhi's innings was folded up for 110 in the 18th over.
Dilshan and Mishra scored 25 and 31 respectively for Delhi in the losing cause.
Akhtar had Sehwag (0) for caught behind in the first over and sent Gambhir (10) packing in his second over before delivering a fatal blow to Delhi with the wickets of AB de Villiers (7) and Manoj Tiwary (9) in successive balls in his third over to finish the spell 4/11.
What a comeback he has made. A fortnight ago he was not sure of IPL stint after being banned from playing cricket. It was only after Pakistan's Prime Ministerial Office intervened to strike a deal with the warring parties - PCB and Akhtar - he was allowed to play in IPL. He came, he bowled and he conquered. Akhtar minus antics&furies is an asset to cricket.
Knight Riders jacked up its position to fourth in the points table with 10 points from five wins while Delhi's slide continued from pole after four defeats and were now behind Kolkata at fifth with four wins and five defeats.
Earlier, Daredevils' bowlers unleashed a tight line and length to stifle Knight Riders batsmen as Kolkata side crawled to their lowest ever in the event.
Delhi seamers gave little away on a sporting wicket. Yomahesh and Maharoof plucked two wickets each while Sangwan claimed one. Ever reliable McGrath bowled a miserly spell of four overs for only 22 runs.
Salman Butt top-scored for Kolkata with 44-ball 48. David Hussy was the other major contributor with run-a-ball 31.
Kolkata openers Butt and Chopra justified their skipper Ganguly's decision to bat first forging a fine 35-run stand in five overs.
India U-19 left-arm seamer Sangwan drew the first blood dismissing his fellow Ranji player Chopra caught Maharoof at mid-off.
The next man in Ganguly sent Yomahesh out of the park over long-on off a free-hit. However the lanky medium pacer from Tamil Nadu had the last laugh when he defeated the Prince of Kolkata with a short of good length to rearrenge his woodwork.
The in-form Hussey joined Butt in the middle and the pair resurrected Kolkata innings with 40-run stand.
Pakistani southpaw although very watchful but did not curb his natural game and let loose a flurry of attractive shots, including his trademark cuts. He hit seven boundaries in his 44-ball knock before slicing Yomahesh's wider one outside the off-stump straight into the hands of McGrath at deep third-man. At this point of time Kolkata's scorecard read 87/3 in 14th over.
Delhi seamers' stifiling line coupled with some sharp work in the field put skids on the run rate in the middle overs. Kolkata trying to up the ante lost too many wickets and most importantly the rhythm of Hussey (Jr) was spoiled for want of partners.
However Hussey's final slurry ensured Kolkata the respectable total. The Aussie amassed 20 runs in the Maharoof's two overs.