His most telling intercession, however, came midway through the evening session, when he returned in the 39th over to lively up what had been a meandering South Africa innings.
At 131 for 3, Temba Bavuma had been settling into a dogged but essential stay, in partnership with his captain, Faf du Plessis.
He was decisive and resolute initially to reach 21 from 44 balls at the close of day one, then picked the right time to up the tempo alongside Johnny Bairstow on day two, before smashing three consecutive sixes to go to his hundred when James Anderson was at the other end.
Broad then took over from the Anderson end, De Kock and Rabada falling before the end of the day - the former edging a length ball behind to Bairstow and the latter the victim of a quite brilliant one-handed catch from Stokes at gully.
But England's progress wasn't dented for long. Anderson had taken three for six in four overs.
The embattled Sri Lankan squad received some good news for a change that skipper Dinesh Chandimal, who missed the first Test because of pneumonia, will return but Rangana Herath, the stand-in captain in that record loss, is being monitored after injuring a finger that did not allow him to bat in the second innings.
England's erratic dominance continued straight after the evening drinks break, when Keshav Maharaj, on 1, edged Moeen off the tip of Bairstow's gloves and away through his legs to safety.
Bavuma, shouldering arms to a delivery that swung in and took out his off stump, and Du Plessis, bowled via a thick inside edge, fell inside three balls.More news: Lawyer wants Trump's testimony in 'fake news' suit against Fox
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In their past 19 series they've won 13, drawn five and lost just one - in India in 2015/16.
Stokes had put on 43 alongside Root and did the heavy lifting in a stand of 65 as he and Jonny Bairstow battled the second new ball. Even so, Bairstow had shepherded England to 362, which now seems enough.
There was still joy to be found late on, though, evidenced by Kagiso Rabada's potentially crucial dismissal of Stokes, England's top scorer in the innings, for 58 with a sizzling yorker in the penultimate over of the day.
England assistant coach Paul Farbrace: "I thought it's been a really tough day for the batters".
Toby Roland-Jones was sent in as a nightwatchman and survived the final over to walk back to the pavilion with Bairstow on an unbeaten 33 as England finished the first day on 260-6.
Anderson, England's evergreen strike bowler, was the man of the moment, though, his best figures in a Test innings at Old Trafford - all from the newly christened James Anderson End - leaving Morne Morkel (18 not out) and Duanne Olivier to await their inevitable fate on Sunday.
The review came instantly, but could not save the Yorkshire batsman, whose brilliance did not result in a fourth Test century. The referral showed the ball was clipping the stumps, thus sticking with the umpire's on-field decision.