Jason Holder bowled an inspired post lunch spell as Worcestershire claimed maximum bowling points on day one of the Vitality County Championship match with Durham at Kidderminster.
The West Indies star removed David Bedingham, Graham Clark and Paul Coughlin during an eight over burst which brought him figures of 8-2-26-3.
It helped to reduce Durham to 141-7 at one stage before Ollie Robinson’s aggressive half century led a partial recovery to 244 all out.
But Adam Finch was rewarded for a probing final spell with two wickets in three balls to secure the three bowling points in just 61.3 overs after Durham had chosen to bat.
Worcestershire opener Jake Libby again showed his quality against a challenging attack in making an unbeaten 35 out of 78-4 from 23 overs.
Worcestershire were back playing first class cricket at Chester Road for the first time in four years and both sides were forced into changes because of injury setbacks.
Worcestershire’s in form batter Kashif Ali was ruled out with a back injury suffered during training and Durham pace bowler, Scott Boland, suffered a foot injury during the drawn game with Warwickshire at Edgbaston.
Play got underway half an hour late and Durham captain Scott Borthwick opted to bat on his 34thbirthday as the Dukes ball returned to the bowlers armoury.
But it was not a happy anniversary for Borthwick as the home side struck two early blows.
Borthwick had failed to trouble the scorers when a delivery in the first over from Joe Leach beat his outside edge and hit the top of off stump.
It became 19 for two when Alex Lees (six) pushed forward to Nathan Smith and fell to a low catch by Jason Holder away to his right at second slip, the New Zealander’s 11th wicket of the season.
Colin Ackermann had an escape on 18 when he flicked Holder off his legs and saw the chance put down at mid wicket and David Bedingham survived a confident shout for lbw by Matthew Waite.
The third wicket pair of Ackermann and David Bedingham had to fight hard for runs in the face of some probing bowling.
Durham reached 89-2 at lunch but Holder switched to the pavilion end and struck in the first over after lunch.
Bedingham on 38 went to cut the former West Indies captain but only succeeded in chopping onto his stumps.
Leach bowled a testing post lunch spell and was rewarded when Ackermann (47) went lbw to a delivery angled back in.
Holder, available for the first five Championship matches of the summer, was constantly asking questions and struck again when Graham Clark (5) was lbw working to leg.
Adam Finch replaced Leach and immediately tasted some success as Bas de Leede played a similar shot and perished in the same fashion.
There was further joy for Holder when Paul Coughlin (1) pushed forward Josh Baker snaffled the chance at second slip.
Robinson decided attack was the best policy and received excellent support from Ben Raine during a stand of 61 in 8.4 overs.
The England Lions keeper-batter completed a 41 ball fifty but Waite had the final say when Robinson (55) pushed forward and keeper Gareth Roderick held onto a low catch.
Finch wrapped up the innings with two wickets in three balls.
Raine (43) went for a pull and feathered through to Roderick and Callum Parkinson (0) missed a full toss and was lbw.
Holder finished with 16-5-47-3, Finch 10.3-2-37-3, Leach 12-0-51-2, Smith 11-2-39-1 and Waite 9-0-53-1.
When Worcestershire batted, Roderick (2) was caught behind off Raine and Club Captain Brett D’Oliveira (0) didn’t play a shot and was bowled by Potts.
Jake Libby and Rob Jones initially dug in but then started to reel off a series of fine strokes.
Libby cover drove Potts for four and Jones produced one of the shots of the day when turning de Leede through mid-wicket for a boundary.
The former Lancashire batter cut and cover drove de Leede for successive fours and Libby rocked back to square drive Coughlin to the ropes.
The stand was worth 60 when Jones (32) pushed forward to Coughlin and was lbw and then Adam Hose (5) chopped the same bowler onto his stumps.
Worcestershire Assistant Head Coach Kadeer Ali said: “A very topsy turvy day today. We started off really well with the ball.
“I thought the boys put in a really good shift with the ball and we caught well.
“Durham hit us with a couple of counters and I thought Ollie Robinson played really nicely.
“It’s been an interesting day, an even kind of day.
“I thought we bowled well this morning, a catch went down, a couple of lbw shouts so there was plenty happening.
“But we know at Kidderminster that the first session and a half there is a bit in it for the bowlers. I thought the boys bowled well throughout the innings and pretty with bowling them out for 244.
“That middle session was an interesting one and we were obviously happy with taking six wickets in that session.
“But again I thought they countered and put pressure back on us in terms of anything that was off line and length.
“With the bat, after losing a couple early, I thought Rob Jones and Jake Libby put together a nice partnership and then they’ve hit us back again with two late wickets.”