Richard Oliver scored a superb 179 but leaders Worcestershire surrendered their proud unbeaten record in the LV = County Championship as they went down by seven wickets inside three days to Gloucestershire at New Road.
The 24-year-old struck 23 fours and a six in his 212 ball innings as he achieved his maiden first class century in only his fourth Championship match for the county.
Oliver has also scored four fifties during that period and he has grabbed his opportunity with both hands in amassing 504 runs in eight Championship innings.
The former Shropshire captain shared in a third wicket stand of 215 in 51 overs with Alexei Kervezee (78) – Worcestershire's highest of the season.
But the last eight wickets went down for 113 runs in 33 overs and Gloucestershire paceman Liam Norwell exploited the second new ball in a spell of 4-16 in 6.1 overs.
Worcestershire were dismissed for 360 to set Gloucestershire a victory target of 177 which they achieved with a day and 20 minutes to spare.
There were second innings wickets for Joe Leach (2) and Shaaiq Choudhry but the visitors were able to complete an first away Championship win over Worcestershire since 1986.
Worcestershire were always playing catch-up after a disappointing opening day with bat and ball when losing the toss was a crucial factor in bowler-friendly conditions on the first morning.
But they still hold a healthy lead at the top of the table after winning seven of their 13 games this season and now have a two week break from action before they take on Derbyshire at Derby.
Worcestershire resumed on 154-2 – still 30 in arrears – with Oliver on 84 and Kervezee 50.
Kervezee had an early let-off when David Payne failed to hold onto a mis-timed pull off Benny Howell when running back to long on.
Oliver reached his hundred with a cover drive for four off Craig Miles and he received a standing ovation from his team-mates on the dressing room balcony.
His century came off 137 balls with 14 fours.
Oliver, who scored 292 not out against Warwickshire for the county Seconds this season, then repeated the stroke off Miles' next delivery.
A single by Oliver off Miles steered Worcestershire into the lead in the 48th over at 185-2.
The 150 partnership came up in 39 overs and the duo only needed another nine overs to extend their partnership to 200.
It surpassed Worcestershire's previous best stand of the season – 178 by skipper Daryl Mitchell and Tom Fell against Leicestershire at Grace Road.
The stand was finally broken when Kervezee on 78 pushed forward to New Zealand spinner Mark Craig and was caught behind by Gareth Roderick with the total 247-3.
Oliver went to his 150 off 177 balls with 21 fours, his third fifty having taken just 40 balls.
Tom Kohler-Cadmore (5) presented Craig with a second wicket on his Championship debut after his attempted sweep lobbed up to Ian Cockbain at mid-wicket.
A heavy shower meant lunch was taken 10 minutes early with Worcestershire on 269-4 from 66.1 overs – a lead of 85.
Oliver hammered occasional spinner Chris Dent for six to extend the lead past 100 but he pushed forward to the same bowler and was caught behind by Roderick with the total on 296.
The new ball was taken at 321-5 and Norwell trapped Ben Cox (19) lbw, had then had Leach (14) and Jack Shantry (6) taken at first and second slip respectively.
Choudhry again played well in making 30 before he edged Mark Payne to second slip and Norwell wrapped up the innings by bowling Mitchell McClenaghan (2).
Dent and Will Tavare put on 67 for the first Gloucestershire wicket before the latter was trapped lbw by Leach for 33.
Dent completed his half century before driving Choudhry to Kohler-Cadmore at mid-off where he held onto a good catch.
Leach collected his 30th Championship wicket of the season – and sixth of the match – when Roderick (25) was caught behind by Cox.
But Alex Gidman followed up his first innings century with some more powerful hitting to see Gloucestershire home – 45 not out off 43 balls.