Joe Leach produced another superb performance with the ball for Worcestershire on day one of the LV=Insurance County Championship match with Sussex at the 1st Central County Ground at Hove.
The seamer showed all his class, guile and experience as he exploited bowler-friendly conditions after Worcestershire Club Captain Brett D’Oliveira put the home side into bat.
Leach completed his 17th five-for in first class cricket and his second in a row after 5-41 in the second innings against Leicestershire at New Road.
He ended with the superb figures of 22-4-73-6 before bad light ended play eight overs early and asked questions of all the batters.
Leach is also now the leading wicket-taker in Division Two with 31 scalps this summer, one ahead of Matthew Potts of Durham.
But the other Worcestershire bowlers found it a challenge to provide the same sort of consistent threat or line and length as Sussex recovered from 142-6 to reach 338-9 from 88 overs.
Worcestershire opener and red ball vice-captain Jake Libby returned to the side in place of Ed Pollock after missing the previous two Championship matches with a back problem.
Pakistan leg spinner Usama Mir was handed his Championship debut after previously playing in the opening three Vitality Blast matches.
Sussex were faced with a green-tinged pitch on a sunny and humid morning.
Leach broke through with the final ball of the first over as Sussex opener Tom Clark aimed a shot towards leg but ball flew to Libby who held onto the chance at fourth slip.
The home side were given a searching examination with the ball nipping around in the air and off the pitch.
Ben Gibbon shared the new ball, and Tom Alsop mistimed a drive in the air, which fell just short at cover of D’Oliveira, who immediately left the field after the ball struck his hand.
Adam Finch settled into a good rhythm and began with two maidens and then Leach struck again when he came back into the attack after swapping ends.
Tom Haines (9) had played and missed at the previous delivery but the left hander was undone by an excellent ball which nipped away and he edged to keeper Gareth Roderick.
D’Oliveira returned to the field with a finger strapped up, and he was delighted to see Leach claim a third scalp.
Tom Alsop (19) could only nick another probing delivery, and this time Jack Haynes at second slip made no mistake.
Usama Mir had his first bowl after 18 overs, and Matthew Waite replaced Leach after figures of 8-1-29-3.
Sussex reached 81-3 at lunch and runs initially flowed at a rapid rate during the opening stages of the afternoon session.
But then Worcestershire re-established control as three wickets fell in quick succession, including two for Leach to complete his five-for.
James Coles (48) upper cut Finch into the hands of Leach at third man after adding 72 with Oli Carter for the fourth wicket
Leach then struck twice in the space of three overs.
Haynes held onto a sharp chance at second slip to account for Dan Ibrahim (0), and then Fynn Hudson-Prentice attempted to cut Leach and perished to an excellent catch by Roderick low down in front of Adam Hose at first slip.
Leach was rested after an afternoon spell of 7-2-22-2, and runs again began to flow more freely from Carter and Nathan McAndrew for the seventh wicket.
Matthew Waite broke the stand after adding 59 when Carter (76) cut a shortish delivery, and Libby clung onto the opportunity for a fine catch at backward point.
The floodlights came on, and then the players went off for rain at 205-7 from 59.3 overs with tea taken.
There was another spell when batting looked more comfortable as McAndrew and Jack Carson put on 52.
Usama Mir ended the partnership with his maiden Championship wicket for Worcestershire as McAndrew (65 off 68 balls) only found Finch at mid on after coming down the pitch.
But another useful stand between Jack Carson and Henry Shipley lifted the total past the 300 mark.
They added 85 before Leach collected his sixth wicket shortly before the close as Shipley could only find mid on.
Finch will be unable to bowl for the remainder of the innings after being taken out of the attack for running on the pitch.