Dhawan scored 92 off 50 balls while Williamson contributed 83 off 53 balls.
This was the Sunrisers' ninth win in 11 games with Black Caps captain Williamson at the helm.
Alex Hales and Shikhar Dhawan started the SRH run chase.
The experienced duo was a delight to watch as it completed the chase with utmost calm.
On Thursday they lock horns with a low-on-confidence Delhi Daredevils (DD), who are now lying in the bottom of the table with with six points.
Jerry Brown has an enviable budget surplus - he wants to save it
One controversial item: health coverage for all undocumented immigrants living in California. "They're not going to get any more". The Legislature can approve its version with only a simple majority, so the Democrats who dominate both chambers are in control.
It will be a great victory for Hyderabad as it was not only their sixth consecutive win in this year's IPL but they win this match on the basis of their batsmen's performance which was worrying since quite some time. Kane Williamson has a dream bowling attack but has been an astute leader as well while making bowling changes and attacking the opposition, nearly choking the batsmen to a false shot.
Earlier, Rishabh Pant helped Delhi reach what looked to be an above par total.
Pant was unstoppable in his unbeaten knock as he toyed with arguably the best bowling attack in the competition, single-handedly giving a fighting chance to a struggling Delhi.
He smashed 15 boundaries and seven sixes in his 63-ball knock and remained unbeaten.
Shakib Al Hasan proved to be the pick of the Sunrisers bowlers with figures of 2 for 27 from his four overs.
The Bangladeshi spinner claimed Roy's wicket right in the next delivery, giving the hosts no room to recover with two wickets for 21 runs with both Prithvi Shaw and Jason Roy dismissed at 9 and 11 runs respectively to give way for skipper Shreyas Iyer and Rishabh Pant. That was only the second six of his innings, but he proceeded to blast five more in the final overs, including taking Bhuvneshwar Kumar (1-51) for three in a row to end the innings in emphatic fashion. Rajasthan Royals who are now on eight points have a game in hand as compared to the two teams above on 10 points. He got towards the a hundred in a similar manner, muscling a full throw from Kaul for over mid wicket. The way Pant took on the likes of Shakib, Kaul and Bhuvenshwar Kumar was commendable. After initially walking across to give the impression of trying to scoop the length over short fine leg, he quickly opened up his wrists, turned around the bat face and ramped it over short third man. It was a rare off day for its India pacer.