Four players saw yellow as Lansdowne dug deep to end Belfast Harlequins’ recent winning run.
‘Quins lost for the first time in six AIB League and Cup outings as the hosts’ replacement hooker Gavin O’Meara scored late.
Front row rivals Paul Doran-Jones and Niall Conlon were sin-binned in the 17th-minute, and ‘Quins player-coach Andy Ward (21) and Lansdowne winger John Coleman (38) were also flashed yellows.
After a scoreless opening half, Andrew Geraghty kicked Lansdowne in front before ‘Quins centre Keith Pyper cut through for a 47th-minute try. However, a powerful lineout drive saw O’Meara clinch the win.
Lansdowne 8 Belfast Harlequins 5, Lansdowne Road (back pitch)
Scorers: Lansdowne: Try: Gavin O’Meara; Pen: Andrew Geraghty
Harlequins: Try: Keith Pyper
HT: Lansdowne 0 Harlequins 0