Steve Cotterill's side almost turned in the textbook away performance against their in-form Welsh opponents but were undone by a Mason goal on 70 minutes.
The manager then gambled with a triple subsitution on 78 minutes but his men were unable to force an equaliser.
Defeat leaves the Reds just a point above the relegation zone but their display gives hope of a climb up the table over the next few weeks.
Source: FOOTYMAD
