Gloucestershire batted through the second day to finish 79 runs ahead of Essex with three of the first innings wickets in tact.
In reaching 352-7 they obtained four batting bonus points for the first time this season with Matthew Windows scoring 118 in five hours at the crease.
The 27-year-old hit 23 boundaries in his 224-ball innings to tilt the balance of the match in favour of his side on a day when the Essex bowlers were made to toil.
Essex were given the early boost of a wicket with the first ball of day when Ronnie Irani had Jack Russell edged behind the stumps.
Within five more overs two further wickets were claimed - those of Kim Barnett, lbw to Mark Ilott for 17 although a long way down pitch, and Tim Hancock, beaten by a ball that swung late to remove the off bail when he had scored 25.
At 44-3 Mark Alleyn joined Windows and the pair took their side to lunch at 115-3.
Having posted a fourth-wicket partnership of 89 in 35 overs, Alleyn was trapped on his front foot by Irani for 43, but the arrival of Ian Harvey to join Windows and the introduction of Peter Such and Rickie Anderson into the attack brought a volley of runs.
In eight overs, Gloucestershire gained 46 runs with 11 boundaries as the ball skipped over the fast outfield. Windows reached 50 from 127 deliveries with a cover boundary - one of nine in his innings thus far.
Australian overseas player Harvey was becoming an imposing figure, but he gave Anderson his first championship wicket when he was hit on back foot and judged lbw when he had scored 29.
Windows moved into overdrive as he cut and drove to reach a chanceless century. His second 50 had taken 40 deliveries as he gathered 11 more boundaries.
It was Such who broke through Window's defences when the batsman played a tired shot to cover and was beaten by a little turn offered by the wicket. His demise signalled the opportunity for Jeremy Snape to take centre stage.
The ex-Northamptonshire man had already kept Windows company in a partnership of 102 and had seen Gloucestershire ease past Essex's first innings.
He began to play confidently, punishing deliveries late in the day.
Snape reached a 109-ball half-century with nine boundaries and lost Martyn All for 11 to a fine catch from Tim Walton at cover point off Ashley Cowan.
However, Snape remained unbeaten on 75 when a sudden shower curtailed play by three overs shortly after Gloucestershire reached their fourth batting point.
Essex's bowling and fielding was keen, with Irani (3-34 from 17 overs) and Ilott (1-70 from 24 overs) the pick of the bowlers, with the latter varying his pace intelligently.
Converted for the new archive on 19 November 2001. Some images and formatting may have been lost in the conversion.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article