The Scarlets consolidated their position amongst the frontrunners on the table when they beat Zebre 31-24 in Parma on Saturday.
Three kicks from Carlo Canna gave Treviso the early initiative. However, tries from Jonathan Evans, Aaron Shingler and DTH van der Merwe gave Scarlets a commanding half-time lead.
Aled Thomas secured the bonus-point with a try just after the break before Jonathan Evans added his second to complete the rout. The home side mounted a late surge with tries from Dries van Schalwyck and Giovanbattista Venditti troubling Scarlets but it was not enough as the visitors held out for victory.
Zebre opened the scoring after just three minutes, Canna knocking over a drop-goal to give the hosts an early lead. This advantage was doubled three minutes later as the Zebre fly-half made it a six-point lead for the Italians.
This lead did not last long as Jonathan Evans scored the first try of the match for Scarlets. The scrum-half stole the ball before running in to score, Rhys Patchell added the conversion for his team to take the lead.
Canna added a second drop-goal to his personal tally after 20 minutes, nudging the hosts back into the lead. This lead lasted 15 minutes before the Welsh visitors scored their second try. Good handling between Tadgh Beirne and DTH van der Merwe played in Schingler to go over. Patchell's conversion made the score 9-14.
In the 38th minute, Scarlets scored their third try. A long spell of pressure inside the Zebre 22 led to a quick move across to Van der Merwe who scored well in the corner. A third successful conversion from Van der Merwe made the score at the break 9-21.
Just five minutes after the break, Scarlets secured the bonus point. Jonathan Davies punched through the Zebre defence before playing in Aled Thomas to finish well to make the score 9-26. Scarlets continued the rout in the 50th minute, Jonathan Evans scoring his second of the match and fifth of the season.
The hosts scored their first try of the match through van Schalwyck after 63 minutes. Canna converted to take the score to 16-31. Zebre's late surge continued as they scored a second try through Venditti with ten minutes to play.
However, the conversion was missed to leave the hosts 10-points adrift. The home side earned themselves a bonus-point with a last-gasp penalty from Canna to make the final score 24-31.
Try: Van Schalkwyk, Venditti
Pens: Canna 2
Drop goals: Canna 2
Tries: J Evans 2, Shingler, Van der Merwe, Thomas
Cons: Patchell 3
Zebre: 15 Dion Berryman, 14 Mattia Bellini, 13 Tommaso Boni, 12 Tommaso Castello, 11 Giovanbattista Venditti, 10 Carlo Canna, 9 Marcello Violi, 8 Andries Van Schalkwyk, 7 Johan Meyer, 6 Derick Minnie, 5 Federico Ruzza, 4 Quintin Geldenhuys (c), 3 Dario Chistolini, 2 Tommaso D'Apice, 1 Bruno Postiglioni
Replacements: 16 Carlo Festuccia, 17 Andrea De Marchi, 18 Guillermo Roan, 19 Gideon Koegelenberg, 20 Valerio Bernabò, 21 Guglielmo Palazzani, 22 Matteo Pratichetti, 23 Edoardo Padovani
Scarlets: 15 Aled Thomas, 14 DTH van der Merwe, 13 Jonathan Davies, 12 Hadleigh Parkes (c), 11 Steff Evans, 10 Rhys Patchell, 9 Jonathan Evans, 8 Will Boyde, 7 James Davies, 6 Aaron Shingler, 5 Tom Price, 4 Tadhg Beirne, 3 Werner Kruger, 2 Ryan Elias, 1 Wyn Jones
Replacements: 16 Emyr Phillips, 17 Rob Evans, 18 Samson Lee, 19 Jake Ball, 20 Josh Macleod, 21 Gareth Davies, 22 Dan Jones, 23 Gareth Owen
Referee: David Wilkinson (Ireland)
Assistant Referees: Kieran Barry (Ireland), Filippo Bertelli (Italy)
TMO: Simon McDowell (Ireland)