SRH were defending a massive total, thanks to brutal knocks from Williamson and Dhawan but totals of 192 have been chased down before with alarming regularity.
And Siraj was faced against Sanju Samson, who had already hammered a hundred this season and the dangerous Sam Billings.
It helped that Bhuvneshwar Kumar bowled a superb first over and it did not help that Siraj conceded three boundaries off his first four deliveries to Billings. It looked like DD would get off to the kind of start they desperately needed - SRH under pressure.
And just then Siraj pitched full and on the pads but Billings clipped uppishly only to find Deepak Hooda gleefully accept a simple catch at midwicket. Siraj had struck in his first over.
That was not the end of it. He came back for his second spell to see off Samson, who was en route another of his hurricanes. A dream debut had been sealed. Siraj was on top of the world.
But it was not an easy day - he had just been informed of his maiden IPL game in the morning and there must have been butterflies in his stomach.
I got to know in the morning that I would get to debut but I was fully prepared," Siraj told iplt20.com
after the match and conceded he was under pressure but understood the need to deal with it as best as he could. "When I was running in to bowl the first ball, it felt like someone had caught my feet. But I was more relaxed after that." And the famous SRH team bonding sessions have obviously helped. Senior pacers like Bhuvneshwar and Ashish Nehra are easing going guys, who are only too eager to help. (SRH vs DD: David Warner hails 'exceptional' Bhuvneshwar Kumar, Siddarth Kaul after win over Delhi Daredevils)
"We have bonded well together and I have learnt a lot from Bhuvi and Ashish bhai. God willing, I can do even better in the next match.
Siraj said getting those two wickets was a good feeling and he understood the importance of bowling dot balls to some of the most attacking batsmen in the league - pressure can do funny things to the best in the business.
It was a night of triumph for the Sunrisers who edged past Mumbai Indians to nestle in at No.2 in the points table. It was also a surreal night for Mohammed Siraj, whose primary concern now is to pick more wickets for his IPL team - isn't it so much better than wondering how he can buy a bigger house for his parents? That, certainly, is already settled.