The Dublin side were 13-12 ahead going into injury time, but two late tries by Brendan Cuttriss and Tim Ryan saw the visitors win 24-12, and so they stay just ahead of Garryowen on points difference.
The Limerick side stay hot on the Cork outfit’s heels following an equally dramatic victory over midtable Lansdowne at Dooradoyle. Garryowen’s hero was replacement out-half Eoghan Hickey, who landed the injury-time penalty that gave them their 16-15 win.
The other top sides also enjoyed the weekend: Shannon travelled to Dublin and gave Terenure a lesson to win 27-12 and retain third place, while Clontarf made the journey north to give a similar beating to Belfast Harlequins, collecting a bonus point in their 27-16 victory.
That gives the top of the table a familiar look — Con lead, with Garryowen, Shannon and Clontarf in hot pursuit. Elsewhere the Connacht derby ended all square, Galwegians and Buccaneers each managing 18 points, while Blackrock-UCD ended with the students eight points adrift, 29-21.
Dolphin’s long journey north ended in defeat as Ballymena notched only their second win of the season at home in Eaton Park, 19-12, but fifth-placed UL Bohemians’ season took a stumble when they lost 22-21 to visitors Dungannon.
In Division Two, table-toppers Greystones beat Young Munster, 38-15. Old Belvedere, in second place, kept on the pressure with a 23-15 win over visitors Highfield. The Cork derby saw UCC beat Midleton 18-6.
In Division Three Ballinahinch stay top, despite having their game with Bruff postponed (Connemara-Wanderers was also postponed). Instonians moved to second place following a grinding 6-3 win over Corinthians. Portadown remain rooted to the bottom of the table with one point after losing 18-6 to Banbridge.