Worcestershire 180 (Waite 60, van Beek 48, Phillip 5-65, Bailey 3-22) and 223 for 9 (van Beek 44, Hose 41, Phillip 4-77) drew with Lancashire 177 (Waite 3-38)
Worcestershire sealed their highest position in the Vitality County Championship since it was split into two divisions in 2000 after drawing with relegated Lancashire at Visit Worcestershire New Road.
They secured sixth spot in Division One after recovering for the second time in the game from a precarious position with the bat thanks to the efforts of Matthew Waite, Adam Hose and Logan Van Beek.
It enabled them to surpass their previous best performance of finishing seventh in Division One in 2011.
Worcestershire have defied the pre-season predictions of being favourites to make an instant return to Division Two after last summer's promotion campaign.
A run of three successive wins against Durham, Kent and Essex effectively made sure of top-flight cricket in 2025.
It was a fitting way for long-serving all-rounder Joe Leach to end his career after being Worcestershire's leader of the attack for the past decade and a haul of 467 first-class wickets for the County.
He received a standing ovation when he came out to bat for the second time in the game and signed off with 30 not out
Worcestershire can be proud of their efforts after the well-documented challenges on and off the field that have confronted them during the past 12 months.
They have shown a tremendous team spirit and an abundance in skill but also their determination in adversity when recovering from challenging positions in games.
Worcestershire triumphed away to Durham after being bowled out for 112 in the first innings and then recovered from 10 for 4 on the first morning to defeat Essex at Chelmsford.
Relegated Lancashire's fate had been sealed on Saturday after their failure to secure a single batting bonus point for the ninth time in 14 games this season.
But there was the encouraging sign of a return to form of pace bowler Tom Bailey.
He had picked up just 16 wickets in his first 10 Championship appearances of the summer but was back to his best against Somerset and Worcestershire with a haul of 11 scalps.
West Indian paceman Anderson Phillip also impressed during his short spell at the club and ended this game with nine wickets.
Phillip struck with his first ball of the day as Jake Libby played too early at the delivery and offered a gentle return catch.
Phillip struck again when Kashif Ali, Worcestershire's leading run-scorer in the Championship this summer, went for a flashing drive and edged through to keeper Matty Hurst.
Gareth Roderick completed 2,000 first class runs for Worcestershire when he reached nine but added only five more before he was run out.
Rob Jones turned Phillip towards cover and he and Roderick set off for a single but the keeper-batter was unable to make his ground before Will Williams direct hit at the non-striker's end.
Jones (17) was lbw after aiming to drive Tom Bailey and Club Captain Brett D'Oliveira lost his middle stump to the same player.
Ethan Brookes was lbw to a delivery angled in by Williams at 78 for 6.
But for the second time in the game Waite led a counter-attack, this time in partnership with Adam Hose.
He pulled Phillip for six and a similar shot off the same bowler brought another boundary.
Hose provided excellent support, mixing solid defence with a series of fine strokes, on driving George Balderson and straight driving Williams to the ropes.
Waite raced onto 37 from 27 balls before he aimed another pull at Phillips but this time picked out Harry Singh at deep square leg.
The seventh wicket pair added 55 in just nine overs.
Hose's determined knock of 41 off 109 balls came to an end when he was lbw to give Bailey his third wicket.
Van Beek advanced to 44 before he holed out to deep mid-wicket off Phillip but then Leach had time to end with a flourish in making 30 not out before bad light halted play at 3,30pm with 41 overs remaining.
