Shannon stuttered to a 22-11 opening day win over Ballymena in Division One as a late try from David Quinlan settled matters at Eaton Park.
The former captain picked up a loose ball off a ruck and ran in from halfway to crown the champions' 200th AIB League game.
Shannon led by 17-6 at the break after tries from full-back David O'Donovan and winger Mark Tuohy. Full-back Dirkie Strydom, who is now a naturalised citizen, kicked a penalty and scrum-half David Drake dropped a goal for the Braidmen.
The hosts controlled much of the second half but could only add a Craig Woods try on 71 minutes.
Zimbabwean Strydom sent over an eighth-minute penalty to edge Ballymena in front as they sought to avoid a hat-trick of losses against the men from Thomond Park.
Their lead lasted all of two minutes as, from a lineout on half way, captain Colm McMahon and young hooker Sean Cronin made good ground for Shannon before numbers out wide saw Tuohy glide in.
Laois man Andrew Thompson converted to make history and take his league points tally to 1,001. He hit the 999 mark thanks to his try in last May's Division One final.
Thompson, the eight-time league winner, was influential throughout and he was hit with a high tackle in the 19th-minute which saw Ballymena prop Simon Shawe sin-binned.
Thompson kicked the resultant penalty and four minutes later O'Donovan was over for Shannon's second try after a neat break from new back Andrew Finn, who has transferred across from arch rivals Garryowen during the close season.
Drake's drop shot, on 29 minutes, left his side 17-6 in arrears, but with former Ireland international James Topping switching from wing to centre in impressive fashion, Ballymena dominated the early part of the second half.
In South African coach Jacques Benade's first league game in charge, the home side had a lot of go-forward ball but Shannon's defence was unrelenting.
They did lose Munster lock Donnacha Ryan to a 69th-minute sin-binning and winger Woods crossed their whitewash two minutes later.
Yet Mick Galwey's men bounced right back when Quinlan romped in after some nifty handling. Interestingly, former Limerick senior footballer Stephen Kelly started on the wing for Shannon this afternoon and looks a decent prospect.
Scorers:
Ballymena: Try: Craig Woods; Pen: Dirkie Strydom; Drop: David Drake.
Shannon: Tries: Mark Tuohy, David O'Donovan, David Quinlan; Cons: Andrew Thompson 2; Pen: Thompson.
