Joe Leach reached 400 first class wickets as Worcestershire bowled out Sussex for 220 and claimed maximum bowling points on day one of the LV=Insurance County Championship fixture at Hove.
The all-rounder brought up the milestone in his career shortly after lunch when he had Faheem Ashraf (2) caught low down at second slip by Jack Haynes.
Leach held his arms aloft in celebration before his teammates mobbed him in recognition of his superb efforts in his 114th match.
He had set Worcestershire on the right track with a superb new ball spell which brought him three wickets as Sussex were reduced to 23-5 after opting to bat.
Leach finished with figures of 13-3-37-4, and all four of his dismissals were left-handers as he posed plenty of problems bowling around the wicket.
He was given good support by Ben Gibbon (13-3-52-3) and Dillon Pennington (14.2-6-45-2) as they continued their recent good form.
But half-centuries from Fynn Hudson-Prentice, James Coles and Jack Carson enabled Sussex to bring about a partial recovery before they were dismissed on the stroke of tea.
Worcestershire openers Ed Pollock and Jake Libby, then gave their side the ideal start and reached 87-0 from 30 overs before bad light ended play six overs early.
The pair batted with great responsibility, with Pollock continuing in the same vein which brought him a half-century against Glamorgan at Cardiff last week.
He showed great concentration and did not succumb to the temptation of Sussex, often placing two fielders back for the shot off his legs, which he favours as he ended unbeaten on 36 from 90 deliveries.
Libby also demonstrated great application and will resume tomorrow on 42 not out from 92 balls.
Worcestershire made two changes from the side which draw with Glamorgan as fit again Azhar Ali and Josh Tongue replaced Taylor Cornall and Ben Cox.
Leach struck in the first over of the day as Ali Orr (1) decided late on to play no shot but inside-edged the ball onto his stumps.
There was more joy for Leach in his second over as Tom Alsop (0) pushed forward and was lbw.
It became 14-3 as Tom Clark (8) tried to work Leach onto the leg side and was also given out leg before.
Pennington came into the attack for Gibbon, and his first delivery accounted for keeper Oli Carter (1), who fenced at a ball of extra bounce and was caught behind by keeper Gareth Roderick.
Leach’s opening spell brought figures of 7-2-16-3, and he was replaced by Gibbon, who picked up his first wicket as Sussex skipper Tom Haines, having battled away for 36 balls for two runs, was bowled by a delivery which cut back in.
Hudson-Prentice and Coles tried to repair the damage for Sussex and adopted a positive approach.
There was a let-off for Hudson-Prentice on 37 when a sharp head-high chance at second slip was put down off Ed Edward.
Worcestershire regained control after lunch with two quick wickets.
Hudson-Prentice, having made 51 off 64 balls, pushed forward to a fine Pennington delivery and nicked through to Roderick.
Leach then celebrated his 400th wicket to leave Sussex on 106-7, but then Coles and Carson added 87 for the eighth wicket.
Gibbon broke the stand when Coles (54) pulled a delivery into the hands of Azhar Ali at deep backward square.
There was more joy for Gibbon as he found the toe end of Henry Crocombe’s bat after making 16, and Pennington held the catch at mid off.
The innings was wrapped up when Carson (58) played Pennington on the on side and was run out attempting a two by Jake Libby’s direct hit.
When Worcestershire launched their reply, Pollock and Libby gave them a solid start in the increasingly gloomy light.
Pollock cashed in on a wide ball from Ashraf with a square drive for four and then drove the same bowler back down the ground for another boundary.
Libby leg glanced Hudson-Prentice for his first four and clipped another wayward ball off his legs to the ropes.
With the floodlights now on, the half-century stand came up from 96 balls, and Libby and Pollock mixed studious defence with putting away the bad ball.