Just a week after delivering their best performance of the season to beat promoted Derby at Fengate, Borough lost the plot late on to lose 38-26 at Dronfield.
The city side are almost certain to finish a creditable fourth, but they will want to finish the season well when hosting neighbours Kettering in their final game on April 23.
Borough competed well in the first-half with tries for Doyle Gordon, who forced his way over from close range, and Willis Ingleby following some fancy footwork. It was 14-12 to Borough at the break and when in-form winger Rob Jacobs finished off a simple move from the backs for 19-12 it was looking good.
But Borough then went completely off the boil. They moved away from the game plan that had worked so well and kep getting on the wrong side of the referee as the home side ran in four second-half tries.
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Ingleby managed to sidestep over for his second try which at least guaranteed a a bonus point for scoring four tries,
Borough coach Shane Manning said: “It was a complete contrast to last week. Everything we did so well the previous week went out the window. Our support play was poor as was our option taking at times.”