Man of the match Tadhg Bennett was the toast of Shannon after his last minute penalty earned his side a draw in the latest installment of the local derbies between these two great rivals.
Garryowen led after eight minutes when referee Michael Black reversed his original decision to award a penalty to Shannon and Declan Cusack, from 45 meters and six in from touch, brought cheers from the Garryowen supporters.
Shannon suffered another blow after twelve minutes when scrum half Rob Guerin had to retire injured and was replaced by Alan Bennie.
To compound problems for the visitors Tadhg Bennett missed a penalty chance and Garryowen got in for a try after 23 minutes from Adam O'Loughlin.
Straight from the kick-off Shannon were awarded a penalty but Bennett's effort drifted just wide to the left of the posts.
Shannon's problems increased when David Quinlan was sin-binned for a professional foul as Garryowen almost got in for another try and from the subsequent penalty Cusack made it 11-0.
Finally Shannon got a lucky break four minutes from the interval. Tadhg Bennett charged down an attempted clearance and won the race to touch down for a try that he was unable to convert.
A fourth penalty by Cusack made it 17-5 but within a few minutes of the restart Bennett finally found the range to give Shannon hope of a comeback.
Bennett landed another penalty after 51 minutes to further narrow the gap when Garryowen were penalised for a scrum infringement and the fly half struck again when this time a Garryowen player was yellow carded to make it 17-14.
Bennett tied it up after 64 minutes when Garryowen were penalised for being off their feet.
It looked over for Shannon when Cusack landed his fifth penalty after 75 minutes but just at the finish Bennett earned the draw for Shannon with his fifth successful kick at goal.
Scorers Garryowen: Adam O'Loughlin try, Declan Cusack 5 pens,
Shannon: Tadhg Bennett try, 5 pens.
Garryowen: Ronan O'Mahony; Adam O'Loughlin, Corey Hircock, Declan Cusack, Alan Gaughan; Fergal Lawlor, Neil Cronin; JP Cooney, Dave Rowley, Declan Lavery; Frank McKenna, Dave Sherry; Paul Neville, Lemeki Viapula, Kieran O'Gorman.
Replacements: Alan McMahon, Peter O'Shea, Alan Kennedy, Conor Hartigan, C O'Shea.
Shannon: Mossie Lawler; Shane McNamara, Richie Mullane, John Clogan, Mike Darcy; Tadhg Bennett, Rob Guerin; Les Hogan, Diarmuid Fitzgerald, Kevin Griffin; Dan Heffernan, Ken Hanley; Stephen Keogh, James Murphy, David Quinlan.
Replacements: John Deegan, Killian O'Neill, Ger McNamara Leonard Mullane, Alan Bennie.
Referee: M Black (IRFU).