DURHAM battled gamely but only when the game was almost up did they muster serious resistance during the evening session at Bristol.
It still looks a lost cause as they ended the third day on 171 for four in their second innings, still 273 behind.
Taking only four points from their sixth defeat of the season will end their promotion hopes as they will be 24.25 points behind Gloucestershire, who will move into third place.
With Glamorgan heading for defeat against Northampton, the Welshmen's visit to Riverside for the final match on Wednesday will now be a dead duck instead of a promotion decider.
The resistance came in a fourth wicket stand of 101 between Martin Love and Gary Pratt. The left-hander enjoyed a purple patch after tea when he repeatedly caressed the ball to the off-side boundary, hitting seven fours in two overs off Ian Harvey and Jonathan Lewis.
Pratt raced past his partner and in the evening session had added 57 compared with Love's 24 when he went down the pitch to left-arm spinner Ian Fisher and was stumped for 62.
It left Pratt 11 short of his 1,000 first-class runs for the season and he was clearly kicking himself as he departed, having hit 11 fours in his 90-ball innings.
Patience was his virtue when he made 150 against Northampton at Riverside, when he relied on orthodox strokes. But perhaps encouraged by the coach he has since started trying to sweep the spinners and his attempts at the stroke yesterday signalled that he was too anxious not to lose momentum.
Love, who had again been off the field in the morning with his damaged thumb, continued to battle it out and was on 49 at the close. Nicky Peng played several fine strokes but also had a couple of narrow escapes against the spinners in reaching 15 not out.
Resuming on 53 for two, 209 ahead, Gloucestershire declared at 288 for seven in their second innings, setting Durham a victory target of 445 in 147 overs.
They reached 42 without loss, then three wickets went down without addition before Love again showed that there were no particular terrors in the pitch or the home attack.
If Durham were to have any chance of turning things round yesterday they needed early wickets from Shoaib Akhtar.
But in his first over a sliced drive by nightwatchman Martyn Ball flew just to Pratt's right at backward point and the fielder was unable to hang on.
Shoaib knocked out Ball's middle and off stumps with a rapid yorker in his next over and almost forced Jonty Rhodes to fend to short leg.
But Rhodes and Matt Windows succeeded in keeping out the Pakistani, and although Liam Plunkett came on to bowl an excellent spell, the danger had passed for Gloucestershire.
Plunkett had two for 23 in his eight-over burst and could have had more wickets, Rhodes surviving an inside edge on five which Phil Mustard failed to hang on to low to his left.
The wicketkeeper also fumbled a stumping chance much later in Rhodes' innings, heightening the mystery as to why he continues to be preferred to Andrew Pratt.
Rhodes, in his final appearance at Bristol, went on to complete his second century. He has announced he will not be coming back for a second season and received a standing ovation for his for 102.
There was an element of luck about both Plunkett's wickets as they came from attempted pulls, with Matt Windows totally miscuing to mid-off.
But the rewards were no more than the 18-year-old Teessider deserved and he might have had Ian Harvey third ball when he edged just short of Paul Collingwood at first slip.
Harvey's eyes lit up when Nicky Phillips came on at 123 for five and in his last four overs before lunch the off-spinner conceded 43 runs.
Harvey twice hit him over wide long-on for six in racing to 41 off 36 balls before edging Shoaib to Mustard straight after lunch.
Although Graeme Bridge took four wickets in the first innings, Durham's gamble on playing two spinners failed to produce the desired results for the second successive match.
They had combined match figures of seven for 384, compared with Shoaib's seven for 78, and with Collingwood carrying little threat as the third seamer the bowling resources were very threadbare.
Rhodes finally handed Bridge his wicket as he went down the pitch and was stumped two balls after reaching his 135-ball century.
Jack Russell spoilt Plunkett's figures in a breezy unbeaten 34 before the declaration came, leaving Durham 51 overs of the third day to survive.
Jon Lewis and Gordon Muchall battled through to the 14th over before three wickets went down in 11 balls. After the openers departed, both bowled, Collingwood fended his fourth ball, a lifter from Lewis, to third slip.
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