Jack Aitchison’s deflected shot and Liam Shephard’s stoppage-time goal on the counter ensured the Shrimps remained second-bottom of League Two.
Nine losses a third of the way through the season is a damning statistic but this one came against the best side to have visited the Globe Arena so far.
Excellent in possession, Forest Green were eventually good value for their win as they bossed the second period after an even first 45 minutes.
Nevertheless, they enjoyed a slice of luck when Aitchison’s shot took a wicked deflection off George Tanner on 75 minutes to open the scoring.
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It was what they deserved, however, as they got on top of a Morecambe side who had matched them for the first hour but failed to take advantage of the chances that came their way.
For good measure, they also saw Lewis Alessandra sent off late on for a second booking, meaning he misses Saturday’s trip to Stevenage.
It was a miserable end to the attacker’s evening after he came close to opening the scoring on the quarter-hour.
Dominic Bernard’s header back fell short, and although Alessandra beat keeper Joe Wollacott to the ball, his shot was cleared off the line by Liam Kitching.
Alessandra and Cole Stockton were off target with other attempts, while at the other end, Ebou Adams headed narrowly over just before half-time.
However, the visitors went through the gears in the second half with Morecambe unable to do much more than clear the ball and invite pressure back upon themselves.
They had a slice of luck just before the hour when Steve Old seemed to bundle over Matty Stevens inside the area, only for play to be waved on.
Aitchison and former Shrimp Aaron Collins were introduced midway through the second half, changes which paid off late on.
Lovely play released Joseph Mills down the left and, having found a yard of space, Aitchison was closed down by a number of home defenders.
His luck, however, was well and truly in as a deflection off Tanner completely wrongfooted Barry Roche and gifted the visitors the opening goal.
Yet, late on, and with some home fans frustrated by what they felt was unnecessarily cautious attacking play from the Shrimps, Bentley’s players fashioned two fine chances.
The first ended with the ball dropping to Old, six yards out, only for him to lash it wildly off target.
Sam Lavelle then stepped forward from the back and was brought down 20 yards out, only for Luke Conlan to waste the resulting free-kick.
With frustration building, Alessandra – who had been cautioned midway through the second half for a mistimed challenge – was sent off for a second such error in the 90th minute.
Further salt was rubbed into the Shrimps’ wound in the last of four added minutes when Forest Green broke and the ball was laid across to Shephard, whose fierce finish gave Roche no chance.
Morecambe: Roche, Tanner, Lavelle, Old, Conlan, O’Sullivan, Kenyon (Miller 80), Brewitt (Wildig 69), Ellison, Alessandra, Stockton. Subs not used: Halstead, Sutton, Howard, Mendes Gomes.
Forest Green Rovers: Wollacott, Shephard, Bernard, Rawson, Kitching, Mills, Winchester, Adams, Morton (Collins 65), Frear (Aitchison 65), Stevens. Subs not used: Thomas, Allen, McCoulsky, Mondal, Taylor.
Referee: Matt Donohue.