A high-scoring encounter at Parc y Scarlets on Sunday saw the Welsh region edged out visiting Connacht 32-30 with eight tries scored.
Jonathan Davies' try and two Rhys Priestland penalties gave the Welsh region a 13-6 lead at the break, while Dan Parks responded for the Irish province with a pair of three-pointers.
But the hosts dominated the early stages of the second half and seemingly secured the victory with touchdowns from Gareth Davies and Josh Turnbull.
However, Connacht continued to fight and reduced the deficit to two points with scores via Kieran Marmion, Fionn Carr and Robbie Henshaw.
Although Gareth Maule went over to finally seal the win for the home side, Eoin McKeon crossed the whitewash in the last minute to rescue two bonus-points.
The Galway-based outfit have shown a marked improvement over recent weeks and went into the game looking for a top-six position. But they got off to the worse possible start as the hosts took advantage of a lapse in concentration in the visiting defence.
Welsh international Davies was the one who eventually touched down to take the Scarlets 7-0 ahead with just a minute on the clock.
Despite that initial setback, Connacht gradually eased their way into the game and successive penalties from Parks reduced the deficit to one point.
Simon Easterby's men responded, though, and regained control of proceedings through the boot of Priestland who kicked two three-pointers to give them a 13-6 advantage at the break.
The Scarlets opened the second half with far more vigour and intent and Pat Lam's side cracked when Davies scampered over.
Two minutes later they crossed again, this time through back-rower Turnbull, before Connacht mounted a comeback through Marmion, Carr and Henshaw tries.
Maule crossed the whitewash to give Easterby's team breathing space in the final moments, but the visitors refused to lie down and McKeon touched down to just about keep the Irish province in the race for sixth.
Tries: J Davies, G Davies, Turnbull, Maule
Cons: Priestland 3
Pens: Priestland 2
Tries: Marmion, Carr, Henshaw, McKeon
Cons: Nikora 2
Pens: Parks 2
Scarlets: 15 Liam Williams, 14 Kristian Phillips, 13 Jonathan Davies (c), 12 Olly Barkley, 11 Jordan Williams, 10 Rhys Priestland, 9 Gareth Davies, 8 Sione Timani, 7 John Barclay, 6 Josh Turnbull, 5 Johan Snyman, 4 Jake Ball, 3 Rhodri Jones, 2 Ken Owens, 1 Phil John
Replacements: 16 Emyr Phillips, 17 Rob Evans, 18 Jacobie Adriaanse, 19 Richard Kelly, 20 Lewis Rawlins, 21 Rhodri Williams, 22 Aled Thomas, 23 Gareth Maule
Connacht: 15 Robbie Henshaw, 14 Tiernan O'Halloran, 13 Eoin Griffin, 12 Dave McSharry, 11 Fionn Carr, 10 Dan Parks, 9 Kieran Marmion, 8 Eoin McKeon, 7 Eoghan Masterson, 6 John Muldoon, 5 Mick Kearney, 4 Aly Muldowney, 3 Rodney Ah You, 2 Jason Harris-Wright, 1 Denis Buckley
Replacements: 16 Dave Heffernan, 17 Ronan Loughney, 18 Nathan White, 19 Michael Swift, 20 Andrew Browne, 21 Frank Murphy, 22 Miah Nikora, 23 Darragh Leader
Referee: Neil Paterson (Sco)
Assistant referees: Wayne Davies, Martyn Lewis (both Wal)
TMO: Tim Hayes (Wal)