Moeen Ali and Tom Fell hit half centuries as Worcestershire launched a strong reply to Middlesex's 309 all out on the second day of the LV = County Championship match at Uxbridge.
Joe Leach picked up three wickets in the space of 11 balls to quickly wrap up the home side's first innings after play got underway at 1.10pm following morning rain.
Then Moeen made 54 and Fell 75 not out as Worcestershire reached 195-3 off 71 overs by the close – 114 in arrears with two days remaining.
There were also important contributions from skipper Daryl Mitchell, who blunted the Middlesex attack until the new ball lost its shine, and Alex Gidman on his 34th birthday and in his 200th first class match.
Middlesex were able to resume on 289-7 after the loss of 16 overs to the elements.
But Leach took his wicket tally for the season to 35 in just five and a half matches with his one, two, three blast.
First to go was James Harris (1) who was adjudged lbw by a ball which kept low.
Leach made it two wickets in two balls when Toby Roland-Jones (0) edged through to Alex Gidman at first slip at 298-9.
It means that Worcestershire have now taken the maximum bowling points in 35 of their last 36 Championship matches.
Tim Murtagh survived the hat-trick ball and Middlesex crept past 300 to secure a third batting point.
But Leach wrapped up the innings with the final ball of his next over as Ollie Rayner (25) was also given out lbw.
Leach finished with figures of 4-81 in 25 overs and Jack Shantry 4-66 in 26 overs.
Murtagh and Roland-Jones took the new ball for the home side against the opening Worcestershire pair of Mitchell and Richard Oliver.
Oliver collected the first boundary in the seventh over via an edge for four to third man off Murtagh.
Harris replaced Roland-Jones and struck in his first over when Oliver (6) was adjudged to have edged through to keeper John Simpson with eight on the board.
Moeen got off the mark with a boundary at the expense of Harris.
Worcestershire rock Mitchell dug in with typical determination and tenacity and waited until his 50th delivery to collect his first boundary – also off Harris.
He then flicked the returning Roland-Jones through mid wicket for another four.
Spinner Ollie Rayner came into the attack for the last over before tea and Moeen straight drove him for four and then flicked him through mid wicket for another boundary.
But only four runs were added after the interval when Mitchell on 18 nicked Roland-Jones through to Rayner low down at second slip. He struck three fours in his 87 ball knock.
Fell came to the wicket at 52-2 and he and Moeen upped the tempo.
Fell edged Murtagh to the boundary but was more convincing in cutting Harris for four and flicking James Franklin off his legs to the ropes.
Moeen drove Franklin through the covers for four and slashed the same bowler over the slips to the boundary.
The 50 partnership came up in 12.3 overs and then Moeen cut Franklin for his 10th four to bring up his 50 off 106 balls.
A stand of 60 in 14.2 overs was ended when Moeen on 54 was deceived by a slower ball from Franklin and lobbed up a catch to Roland-Jones at mid off.
New batsman Gidman got off the mark with an edge for four off Murtagh.
Fell completed 1,500 first class runs in his career when he reached 32 and Gidman started to look more assured and despatched Harris for four.
Fell went to his third 50 plus score of the season – including a century against Yorkshire – from 80 balls with his eighth four off Harris out of 156-3.
By the close the fourth wicket stand between Fell and Gidman was worth 83 in 27overs.
Fell has struck 12 fours in his 127 ball knock and Gidman four boundaries in his 83 ball innings for 30 not out.