Scarlets (20) 35 Tries: J Davies 2, King, Lamont. Cons: S Jones 3. Pens: S Jones 2. Connacht (13) 33 Tries: Carr 3. Cons: Keatley 3. Pens: Keatley 3.
Scarlets wing Sean Lamont is congratulated after his late winner
Sean Lamont scored with almost the last move of the match to give Scarlets victory in a Magners League thriller.
Connacht seemed set to grab a rare win at Parc y Scarlets thanks to a hat-trick of tries from wing Fionn Carr.
But Scarlets exploited the numbers when visiting prop Ronan Loughney was sin-binned, Jonathan Davies crossing for his second try before Lamont struck.
The Scottish flyer's try also claimed a bonus point for Scarlets, with Regan King having crossed in the first half.
Connacht were fresh from their opening-day win over Newport Gwent Dragons and made the more impressive start, with penalties from Ian Keatley on five and 10 minutes putting them 6-0 ahead.
However, despite poor discipline and handling errors, the Scarlets came back into the contest.
Two Stephen Jones penalties were sandwiched by a finely worked try from the home side's first real attack - Jones putting Samoan lock Jonny Fa'amatuainu through a gap before King sent fellow centre Davies over.
Connacht did not let their heads drop when the Scarlets went into a 13-6 lead, though, and got back on terms almost immediately.
Full-back Gavin Duffy did well to collect Jones' restart and the ball was moved quickly to left wing Carr, who finished off an impressive team try.
Connacht seemed to start dictating play towards half-time but suffered a blow when their skipper Frank Murphy got himself sin-binned for a high tackle on Scarlets full-back Andy Fenby.
With the extra man the Scarlets scored an injury-time try, Davies collecting a Jones chip and putting King over by the posts.
Connacht were still without Murphy after half-time but soaked up some early pressure before Carr ran 60 metres for his second try, and Keatley's conversion locked the score at 20-20 on 45 minutes.
The Scarlets had plenty of possession as they attempted to get back into the lead but every attack was littered with poor passes and handling errors.
It took a Connacht transgression for Scarlets to get into the lead when Jones slotted over a 62nd-minute penalty goal.
But Connacht responded with a penalty goal for Keatley three minutes later and then Carr cut inside to complete his treble and put the Irish side 30-23 up.
But Connacht suffered a second sin-binning when Loughney was penalised for kicking a ball out of a ruck, enabling the Scarlets to tie the scores at 30-30 when Davies went in for his second try.
The visitors went ahead for only the second time in the contest when Keatley put over his fourth penalty.
But in a frantic finish the Scarlets eventually got the ball out to Lamont who - seven minutes into injury time - went over for the winning try to send the home fans into raptures.
Scarlets: Andy Fenby; George North, Regan King, Jon Davies, Sean Lamont; Stephen Jones, Martin Roberts; Phil John, Matthew Rees (capt), Rhys Thomas, Lou Reed, Jonny Fa'amatuainu, Josh Turnbull, Johnathan Edwards, Rob McCusker. Replacements: Ken Owens for Rees (76), Iestyn Thomas for John (57), Peter Edwards for R. Thomas (76), Dominic Day for Fa'amatuainu (80), Nic Cudd, Tavis Knoyle for Roberts (57), Dan Newton, Gareth Maule.
Connacht: Gavin Duffy; Troy Nathan, Niva Ta'auso, Keith Matthews, Fionn Carr; Ian Keatley, Frank Murphy (capt); Brett Wilkinson; Sean Cronin, Jamie Hagan, Michael Swift, Bernie Upton; Michael McCarthy, Ray Ofisa; Mike McComish, Replacements: Adrian Flavin for Ofisa (80), Ronan Loughney for Wilkinson (62), Rob Sweeney, Dave Nolan, Shane Conneely, Cillian Willis F. Murphy (57), Miah Nikora for Ta'auso (62), Tiernan O'Halloran.
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