Four wicket Jack Shantry struck a crucial late blow for Worcestershire on the opening day of the LV = County Championship clash with Middlesex at Uxbridge.
Shantry removed century-maker and Middlesex captain James Franklin with what proved to be the final ball of the day as Middlesex closed on 289-7 from 95.1 overs.
The New Zealander and John Simpson had led a recovery with a sixth wicket stand of 170 after Middlesex had been 102-5 shortly after lunch.
But both fell to the second new ball to leave the game finely poised.
Simpson (41) was caught at second slip by Worcestershire skipper Daryl Mitchell and then Franklin, having made 135 off 255 balls with 18 fours, fell at second slip to that man Shantry.
He finished with figures of 4-60 from 22.1 overs.
Shantry also collected the wickets of Nick Gubbins, Paul Stirling and Joe Burns as the visitors dominated the opening third of the day.
Worcestershire kept faith with the side beaten inside two days by Warwickshire at New Road with Ed Barnard left out of the 12.
Middlesex won the toss and elected to bat on a greenish pitch – and Charlie Morris broke through with the first delivery of the game.
England opener Sam Robson departed for nought, edging Morris to Tom Fell at third slip who took a good tumbling catch.
It became 5-2 when former Worcestershire loanee Nick Compton (3) turned a leg stump delivery from Joe Leach into the hands of Richard Oliver at mid wicket.
Compton was slow to depart but the umpires conferred and decided the catch had been taken cleanly.
Shantry came on for Leach after an opening spell of 4-1-11-1.
The left armer enjoyed his first success of the day when Gubbins (19), who was trying to work to leg, was caught by Saeed Ajmal at mid on, the ball looping up in the air off the toe end of the bat to leave Middlesex on 45-3.
Leach switched ends to take over from Morris after his initial spell of 7-1-11-1.
But it was Shantry who made further inroads with the total on 51 as Stirling was trapped lbw for four by a delivery which straightened on him.
Saeed Ajmal came into the attack at 61-4 after 22 overs.
He bowled four overs for eight runs before replaced by Moeen Ali for the final over before lunch when Joe Burns was unbeaten on 43 and Middlesex skipper James Franklin on four.
Shantry and Leach came into the attack after lunch and Australian Test player Burns reached an excellent 50 off 84 balls with five fours out of 87-4.
The Middlesex 100 came up in the 40th over from Shantry as Burns and Franklin completed a 50 partnership from 20 overs.
But in the same over Shantry struck for the third time as Burns (57) was undone by a ball of extra bounce and Fell took a fine low catch away to his left in the gulley with the total on 102.
Franklin and Simpson then joined forces and started to rebuild the Middlesex innings as the 50 partnership was completed in 21 overs.
Franklin gradually accelerated with his half century occupying 122 balls and needing only another 65 to go to three figures.
Mitchell ran the changes in an effort to force a breakthrough and there was a brief period of spin in tandem from the 75th over with Ajmal and Ali until the second new ball was taken at 235-5 from 80 overs.
Franklin was given a life on 120 when Morris at deep backward square failed to hold onto a chance offered from a Leach delivery.
But then the dismissal of Simpson and Franklin tipped the scales slightly in Worcestershire's favour.