Worcestershire's progress was checked by an unbroken sixth wicket of 179 by New Zealand duo Hamish Marshall and Kieran Noema-Barnett on day one of the Specsavers County Championship clash with Gloucestershire at Bristol.
Skipper Daryl Mitchell's side made regular inroads after electing to bowl first in reducing the home side at one stage to 157-5.
Ed Barnard (2), Jack Shantry and debutant Matt Henry picked up wickets while the latter was also responsible for a brilliant run-out.
But Marshall and Noema-Barnett then batted for the remainder of the day and 158 runs were scored between tea and the close of play as Gloucestershire closed on 336-5 from 96 overs.
Marshall, who went to the wicket at 57-3, finished undefeated on 123 from 195 balls with 15 boundaries. It was the 27th first class century of the 37-year-old's career.
Noema-Barnett, aged 28, ended on 84 not out from 132 balls with 15 fours and one six off Moeen Ali – his highest Championship score for Gloucestershire.
An inspirational moment of fielding brilliance from Henry turned things Worcestershire’s way in the morning session after the hosts had progressed to 37-0.
Cameron Bancroft, on 15, played a ball from Joe Leach to wide mid-on and called for a quick single.
With only one stump to aim at, Henry clipped the bails at the bowler’s end with the diving Bancroft just short of his ground.
Ian Cockbain was then lbw to Barnard pushing forward for five with the total on 56 and one run later Gareth Roderick was well held by the diving Ross Whiteley at third slip off Shantry.
Chris Dent batted through the morning session, with just one major scare on 40 when edging Henry just short of first slip.
The left-hander was unbeaten on 41 at the interval with Gloucestershire 89 for three off 32 overs.
Dent followed up his 180 in the previous match against Derbyshire by making 59 off 136 balls, with six fours before he was caught at first slip by Tom Kohler-Cadmore off Barnard.
Gloucestershire Championship debutant George Hankins made 18 before he edged Matt Henry to Whiteley at third slip to give the New Zealander his first wicket for the County.
But that was the end of any tangible success for the visitors as Marshall and Noema-Barnett remained at the wicket for the rest of day one.