Broad got his first wicket at the end of the 62nd over of the match when Ian Bell made a fantastic catch after Kumar Sangakkara sliced Broad's delivery.
Broad then took care of Dinesh Chandimal in the first ball of the 64th over, as the batsman's thick outside edge carried to Alastair Cook at first slip. Next ball Shaminda Eranga went after edging to Matt Prior.
However, as Broad's first wicket in the hat-trick came two overs previously, nobody in the ground, including Broad, initially seemed to realise he had claimed a hat-trick.
Instead, supporters urged Broad on to claim a hat-trick next ball but Kavi Pradeep 'survived'.
There was finally a look of surprise and then realisation on Broad's face when it was revealed over the tannoy that he had claimed a hat-trick.
"I had no idea," Broad told Sky Sports.
"I was listening to the guy that came on the tannoy there and I was thinking 'why is he mentioning the last ball of the over before?', and it clicked that that might be a hat-trick."
Broad becomes the first Englishman to take two Test hat-tricks after having claimed one against India at Trent Bridge in 2011.
- Sports & Recreation
- Kumar Sangakkara
- Alastair Cook