Richard Oliver scored his maiden first class century as Worcestershire continued their fightback on the third morning of the LV = County Championship clash with Gloucestershire at New Road.
The 24-year-old had moved onto a superb 160 not out by lunch out of Worcestershire's 269-4 after featuring a double century stand with Alexei Kervezee.
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.