The Scarlets booked their place in the Champions Cup with a 17-13 win at Treviso to finish sixth in the Pro12.
Treviso dominated the opening period and deservedly went 13-3 ahead at the interval through Davide Giazzon and Jayden Hayward tries.
However, the Italian side couldn't build on their dominance and the Welsh region came back to seal the win through Liam Williams and Steffan Evans touchdowns.
The Llanelli-based outfit's victory over Cardiff Blues last weekend meant that they went into their game with Benetton knowing that a win would be enough for European Champions Cup rugby next season.
Treviso also had their own continental ambitions with them residing just three points above country rivals Zebre in the league table.
But that looked less likely when the hosts opened the scoring as a dominant driving maul resulted in Giazzon crossing the whitewash.
The Italian outfit then threatened through Mat Luamanu's superbly constructed break which almost resulted in a second try.
Although the number eight couldn't get the ball over the line, they won a penalty from the subsequent passage of play which Hayward converted.
Rhys Priestland did reduce the arrears for the Scarlets from the tee, but it was Benetton who consistently looked the most dangerous and it was no surprise to see them score another touchdown through their full-back.
Visiting head coach Wayne Pivac needed a response but it was the home side who continued to have the better chances and it was only Scott Williams' last ditch tackle which prevented another try.
But they improved considerably in the final quarter and Liam Williams took them to within three points before Evans crossed the whitewash to snatch the win.
Tries: Giazzon, Hayward
Tries: L. Williams, Steffan Evans
Cons: Priestland 2
Treviso: 15 Jayden Hayward, 14 Andrea Pratichetti, 13 Luca Morisi, 12 Enrico Bacchin, 11 Simone Ragusi, 10 Sam Christie, 9 Henry Seniloli, 8 Mat Luamanu, 7 Francesco Minto, 6 Paul Derbyshire, 5 Corniel van Zyl, 4 Antonio Pavanello (c), 3 Rupert Harden, 2 Davide Giazzon, 1 Matteo Zanusso
Replacements: 16 Albert Anae, 17 Romulo Acosta, 18 Salesi Manu, 19 Marco Fuser, 20 Meyer Swanepoel, 21 Nicola Cattina, 22 Angelo Esposito, 23 James Ambrosini
Scarlets: 15 Liam Williams, 14 Adam Warren, 13 Hadleigh Parkes, 12 Scott Williams, 11 Steff Evans, 10 Rhys Priestland, 9 Gareth Davies, 8 John Barclay, 7 James Davies, 6 Aaron Shingler, 5 Lewis Rawlins, 4 Jake Ball, 3 Peter Edwards, 2 Ken Owens, 1 Rob Evans
Replacements: 16 Ryan Elias, 17 Phil John, 18 Wyn Jones, 19 George Earle, 20 Rory Pitman, 21 Rhodri Williams, 22 Steven Shingler, 23 Daniel Jones
Referee: George Clancy (IRFU, 72nd competition game)
Assistant Referees: Giuseppe Vivarini, Simone Boaretto (both FIR)
TMO: Carlo Damasco (FIR)