All-Ireland League:Constitution lead Clontarf on points difference at the head of the AIB League Division One, after Clontarf's win over Blackrock College at Castle Avenue on Saturday and Shannon's remarkable fightback against Cork Constitution at Temple Hill yesterday.
Constitution raced into a 17-0 lead but the Limerick team staged a great recovery to snatch a 17-17 draw and a share of the spoils.
The Cork club appeared to be easing toward a fourth straight league win through a Richard Lanes penalty in first-half injury-time and second-half tries from wingers Diarmuid O'Riordan and Cronan Healy.
The result sees Shannon up to third place in the table on points difference from Garryowen.
Yesterday's other match ended in a 19-13 victory for Dolphin over St Mary's College at Musgrave Park. The home side grabbed tries from Peter Owens and Gary Conway with outhalf Barry Keeshan kicking three penalties.
St Mary's responded with tries by former Leinster wing John McWeeney and underage international outhalf Jonathan Sexton, who also added a penalty.
Clontarf managed a hard-fought 26-22 win over Blackrock. The home side raced into a 19-0 lead but a brace of tries from visiting fullback Fionn Carr turned the match into a contest.
Blackrock briefly led at one stage but a try from Johnny Wickham, converted by Matt Nethery, earned the north Dublin club a narrow success.
Garryowen could have topped the table but came unstuck against Buccaneers at Dubarry Park, losing a low-scoring game 8-6. In a game dominated by the respective packs, it was former Garryowen flanker and current Buccaneers captain Conor Hartigan that crossed for the game's only try.
Lansdowne's revival continued with a 17-16 win over Galwegians, the home side celebrating their last club match on the international pitch at Lansdowne Road.
Galwegians were reduced to 14 men when prop Ross Davies was sent off in the first half but it still took a penalty from fullback Robbie Dolan, five minutes into injury time, for Lansdowne to secure their success.
Elsewhere, UL Bohemian ended a two-match losing run with a 15-9 victory over Belfast Harlequins. Dungannon came back from 24-0 down against UCD at Stevenson Park - Fergus McFadden, Ian Keatley and Rob Kearney crossing for tries for the students, who were then held scoreless after the interval as Dungannon won 29-24.
Ballymena continued their rehabilitation with a 29-10 victory over Terenure at Eaton Park.