Another flanker, Joe Campbell, was sin-binned for the Division Two East leaders in the last ten minutes.
This allowed Mountain Ash the time and space to reduce their deficit from 27-17 to 27-24, earning themselves a losing bonus point.
Bedlinog stay in second place after a convincing 33-0 win over Treherbert. Geraint Edmunds, Thomas Hiscock, Gavin Jones, Lee Hevinson and Ben Grzesica scored the five tries to earn the Foxes a bonus point.
Abercynon and Abergavenny also crashed over five tries as they won 36-0 against Rhydyfelin and 33-8 against Ynysybwl respectively, while Fleur de Lys crossed four times in a 38-16 home win over Llantrisant.
Pill Harriers are the new leaders of Division Three East after a 38-10 win at Blaina. The Harriers scored six tries which included a pair from flanker David Tovey. Leighton Burrows, Gareth Hassel, Shaun Dutter and Louis Culverwell scored Pill's other tries.
They go above Garndiffaith, as do Croesyceiliog, after the former visited the later in a match that Croesyceiliog ran out 26-10 bonus point victors.
Llandaff stay top of Division Four East after they beat third-placed Tredegar Ironsides 13-3, with Barry Greenley scoring the only try of the game. Nathan Rees kicked two penalties and a conversion for the home team at Bishop's Field.
Nantyglo stay second after a 25-18 win at Chepstow, in a game where the teams shared six tries between them. Chris Davies and Jason Williams had crossed for the visitors, who won the game thanks to a penalty try.
Division Five East leaders Abercarn scored five tries in a 40-16 win over Bettws while Division Six East table-toppers Hartridge went over four times in a 30-19 victory at Crickhowell.