Worcestershire claimed maximum bowling points after bowling out Durham for 197 on the opening day of the Specsavers County Championship match at the Emirates.
Joe Leach and John Hastings reduced Durham to 18-5 at one stage after five wickets went down in the space of 22 balls.
Then Brett D'Oliveira hit a superb unbeaten 91 off 132 balls with one six and 14 fours as Worcestershire moved into the lead and closed on 213-4 from 43 overs.
The opener shared in stands of 77 with Joe Clarke and an unbroken 74 with Moeen Ali to put Worcestershire into the ascendancy on a day which play finished at 9.50pm.
County skipper Leach opted to bowl first in a game which got underway at 2pm under lights and with a pink duke ball.
It was a move that paid immediate dividends. Former Durham all-rounder Hastings was first to strike as Cameron Steel (5) was caught by Daryl Mitchell at second slip with 12 on the board.
Leach broke through in the next over as Keaton Jennings (6) lost his leg stump – his 41st wicket of the campaign.
Hastings accounted for Jack Burnham (3) who wafted at a ball that moved away and was caught by keeper Ben Cox.
Leach dismissed Graham Clark lbw (1) as he attempted to work the ball on the leg side.
Then Hastings collected the prized wicket of Ben Stokes (0) who was undone by a ball that left him and presented Cox with his second catch.
Paul Collingwood and Ryan Pringle were left to try and repair the situation for the home side and they added 46 before the former on 11 was lbw to Ed Barnard.
Josh Tongue then got rid of Collingwood (25) as Moeen Ali held onto the chance in the gulley region at 64-7.
Durham then staged a revival with the last three wickets adding 133.
Stuart Poynter (43) and Mark Wood (21) featured in a stand of 54 before Wood perished to Ross Whiteley at deep point off Tongue.
Tongue enjoyed another success when he bowled Poynter but further resistance came from Barry McCarthy (29 not out) and Chris Rushworth (30) in a last wicket partnership of 50.
The innings eventually ended when Rushworth attempted to pull Tongue and holed out to D'Oliveira.
Tongue finished with 4-41 from 12.2 overs, Leach 2-45 from 11 overs and Hastings 3-44 from 17 overs.
Wickets also initially tumbled when Worcestershire launched their reply.
Daryl Mitchell (3) pushed forward and was caught behind off Wood with six on the board.
Worcestershire rejigged their batting order in the tricky conditions with Hastings and Leach promoted to three and four respectively – a move they also empoyed in the home game with Northamptonshire.
Hastings made a quickfire 12 before trying to pull Wood and feathering through to Poynter. Then Leach (16) went for a big hit against Rushworth and was held by Clark at deep mid on with the total 59-3.
But D'Oliveira and Joe Clarke played well in adding 77 in just 16.3 overs for the fourth wicket.
D'Oliveira went to an excellent half century off 72 balls with nine fours out of 136-3 but there was no addition to the score when Clarke, after making an impressive 45, lost his off stump to Wood.
Moeen came to the wicket and built another fine partnership with D'Oliveira who pulled McCarthy over mid wicket for six.
He then steered Worcestershire into the lead with a pull for four off Pringle and secured a first batting bonus point.
By the close Moeen was unbeaten on 33 from 40 balls.