Last season's Division One table-toppers Garryowen notched three tries early in the second half to down Dungannon at Stevenson Park.
AIB LEAGUE: DIVISION ONE: Saturday, October 14
DUNGANNON 23 GARRYOWEN 29, Stevenson Park
Scorers: Dungannon: Tries; Gary Maxwell, Glenn Sinnamon; Cons: Richard McCarter 2; Pen: McCarter 3
Garryowen: Tries: Liam Og Casey, Ciaran O'Boyle, John O'Sullivan, Adam O'Loughlin; Cons: Conor Kilroy 3; Pen: Kilroy
Garryowen, with Paul Cunningham again in charge this season after Rob Henderson's transfer to Toulon, pulled 20 points clear of their hosts on Saturday after a powerful third quarter performance.
The first half had been a drab affair only sparked by young prop Casey's fifth-minute try - he came up in support to crash over in the left corner. Garryowen full-back Conor Kilroy missed the conversion and a further penalty before putting his side 8-6 ahead on the half-hour mark.
In between McCarter had landed two penalties, on 9 and 15 minutes, to push Dungannon ahead but Kilroy's 30th-minute effort, from the guts of 50 metres, was well worth the admission price alone.
Davidson's side went ahead again, shortly after the break, when McCarter kicked his third penalty but for the next 15 minutes Garryowen were comfortably in control. They crossed for three tries in the space of nine minutes.
A crossfield kick from out-half Alan Kinglsey was gobbled up by O'Boyle and touched down wide out on the left, O'Sullivan powered over only moments later and O'Loughlin evaded two would-be tacklers to score again in the 58th-minute.
Dungannon mustered two late responses through replacements Sinnamon and Maxwell, both converted by McCarter, to garner a losing bonus point. 'Gannon had a dominant spell during which the Munster-contracted Chris Wyatt, who was making his league debut, was sin-binned. Garryowen claimed their twelfth win in 20 AIB League visits to Ulster as they notched four tries, in total, at Stevenson Park.
Prop Liam Og Casey, wingers Ciaran O'Boyle and Adam O'Loughlin and Munster-capped back row John O'Sullivan all scored as the Limerick men made a winning return to the fray.
Two penalties from new out-half Richard McCarter, who transferred from City of Derry, had Dungannon well in touch - trailing by 8-6 at the break.
But Jeremy Davidson's charges were edged out despite second half tries from Gary Maxwell and Glenn Sinnamon. Former club President Gary Leslie, 36, propped down for 'Gannon.
Dungannon: N Patterson; P Magee, J Bell, G Telford, M Pehi; R McCarter, D Spence; R Mackay, N Brady, G Leslie, R Caldwell, S McCarroll, S Lamb, R Hughes, T Anderson.
Subs used: G Maxwell for Mackay, G Sinnamon for Leslie, M Boyd for McCarroll.
Garryowen: C Kilroy; Ciaran O'Boyle, K Hartigan, F Quaglia, A O'Loughlin; A Kingsley, G Hurley; L Og Casey, D Varley, V Lavery, M Melbourne, E Mackey, P Neville, J O'Sullivan, P Malone.
Subs used: C Wyatt for Mackey, D Sherry for Malone.
Referee: David Keane (Leinster)