Warwickshire's Jonathan Trott scored his first century since returning to cricket from illness but was unable to prevent Sussex seizing control of the contest in LV= County Championship Division One.
Trott left England's nightmare tour of Australia early in November and took five months off from the sport to recover from a stress-related condition.
The 33-year-old hit 106 in Horsham before being caught behind off the bowling of Sussex's Steve Magoffin, who also enjoyed an excellent afternoon, taking four for 74.
Lewis Hatchett was also in fine form with the ball as he finished with three for 70 to dismiss Warwickshire for 333, trailing 80 runs behind after the first innings.
Sussex then built a 284-run lead as Ed Joyce (72) and Craig Cachopa (54) made significant contributions for the hosts, who ended the day 204 for four.
Both eventually fell to Warwickshire's Boyd Rankin, who finished with two for 36 at the close of day three.
Worcestershire's assault on the LV= County Championship Division Two title remains on course after a convincing eight-wicket win over Gloucestershire at Cheltenham.
Worcestershire's victory was sealed within three days but it could have been over even sooner were it not for a superb last-wicket stand from Gloucestershire's Craig Miles (62 not out) and Liam Norwell (78).
Norwell's score was the highest in first-class cricket for a Gloucestershire number 11 and the duo's 137-run partnership made sure Worcestershire had to bat again, albeit needing only 51 to win.
The hosts reached their target in less than eight overs for the loss of two wickets as Daryl Mitchell (15) and Richard Oliver (18) both fell.
Earlier, Worcestershire's Jack Shantry took four for 52 to put his side firmly in command before Norwell and Miles' late efforts.
The win means Worcestershire stay top of the table, 43 points clear of Surrey with a game in hand and 45 points ahead of Hampshire in third.
Surrey lost ground on their rivals after losing to Kent, who kept their own promotion hopes alive with an impressive 89-run win at Guildford.
Darren Stevens was the star of the show as his five for 68 ensured Surrey were bowled out for 213 in their second innings, having been set a target of 303 to win.
Kent's Mitchell Claydon (three for 62) and Calum Haggett (two for 48) were also in form but it was Stevens who took the final five wickets, including that of Tillakaratne Dilshan who had scored 68.
Kent's 24-point win means they climb to 23 points behind Surrey, who are second having played two games more than their opponents.