Durham trail by 32 runs with eight first-innings wickets standing
Having demolished Derbyshire by ten wickets in their Frizzell County Championship opener last week, Worcestershire were dismissed for only 171 in the 53rd over in their first Division Two away match yesterday.
Vikram Solanki again won the toss for the Pears but, after Stephen Peters and Stephen Moore put on 75 for the first wicket, the visitors succumbed to an all-seam attack.
Mark Davies, the tall 24-year-old pace bowler, took the first six wickets to fall for a career-best six for 32.
England paceman Steve Harmison cleaned up the tail to take three wickets on a cold and overcast day before Durham closed on 139 for two off 49 overs.
Worcestershire were dismissed by mid-afternoon on a seaming pitch before struggling in the field despite an early breakthrough.
Debutant Sri Lanka seamer Chaminda Vaas removed dangerman Mike Hussey when the Australian played on for two, but a second-wicket stand of 103 between England one-day international Paul Collingwood and opener Jon Lewis boosted Durham.
Worcestershire began promisingly with Peters and Moore scoring at a good rate. But batting was never easy and, once Davies broke through in the 22nd over, Worcestershire lost wickets at regular intervals.
The fast-medium rightarmer rattled Peters' middle and off stumps after the opener had scored 30. Moore, on 46, soon followed when he became the first of three lbw victims for Davies.
There was little resistance after that, Davies taking six wickets for only nine runs in a devastating 41-ball spell.
Ben Smith offered no shot on the front foot and went lbw for four and captain Solanki had scored only one when he was superbly caught at third slip by Gareth Breese.
Worcestershire were reduced to 114 for five off 33 overs at lunch, when Gareth Batty was trapped lbw by one that kept low.
Only another 57 runs were added after the break and Vaas chipped in with half of them. He was the ninth wicket to fall when he edged Harmison to Collingwood at first slip before Harmison bowled Alamgir Sheriyar.
James Pipe and Matt Mason had earlier lost their wickets, to Davies and Harmison respectively, before Durham were limited to 34 for one off 17 overs at tea.
The free-scoring Hussey went cheaply but, with the pitch easing, Collingwood reached a 77-ball halfcentury. He is unbeaten on 88 and has been severe on any short-pitched deliveries.