As if he had not taken centre-stage enough already, James Anderson was again to the fore with another wonderful exhibition of swing bowling which was rewarded with figures of seven for 42, the best of his career.
But despite the improved batting conditions, it only needed four balls on Saturday for Anderson to take another wicket.
Shai Hope, whose twin hundreds were the backbone of West Indies' series-levelling win at Headingley, top-scored in this innings with 62.
Anderson, bowling from the Nursery End after being warned for running on the pitch at the Pavilion End by umpire Marais Erasmus on Friday, had taken two wickets for four runs in 23 balls and West Indies were 100 for five.
Roston Chase (3) couldn't add to his overnight score before nibbling at one outside off from Anderson and being caught by Jonny Bairstow.
Three maidens followed, and only a Hope single came from the first four overs of a sunny morning.
Broad then had Blackwood given out lbw by but the batsman successfully reviewed after replays confirmed an inside edge.
Instead, it was over to Anderson again to account for the unsafe stroke-maker for just five with an action replay of Chase's earlier dismissal.
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Broad had dropped his second catch of the morning, a much tougher one diving one-handed to his left in his follow-through when a still scoreless Dowrich poked back a mistimed drive.
Broad clung on to Dowrich at mid-on, however, when the Windies wicketkeeper skewed a pull shot off Toby Roland-Jones (1-31), Dowrich falling for 14 to total just 24 runs in the series at an average of 4.80.
Hope remained patient, waiting until lunch was in the offing before he cover-drove Ben Stokes for his first four of the day - from the 54th ball he had faced.
Hope was 60 not out, his latest impressive innings this series, with West Indies captain Jason Holder - dropped off the last ball before lunch - eight not out.
But Alastair Cook at gully was unable to react in time to hold what would have been a spectacular catch.
The 35-year-old moved on to 506 scalps at the venue where he claimed his first, in 2003, by lastly castling Kemar Roach, the wicket ensuring he bettered the 7-43 he bagged against New Zealand at Trent Bridge in 2008.
And so it proved as the tail was swiftly dealt with, setting England a modest target that was seen off with the minimum of fuss.
It snaked past the left-hander's forward-defensive for lbw, before his opening partner Mark Stoneman and under-fire number three Tom Westley took an opportunity to marginally restate their respective credentials for an Ashes winter in an unbroken stand of 72.