Unbeaten Ospreys march on
Ospreys pulled away in the second half to beat Connacht 26-11 and equal their best-ever start to a league season.
Ospreys welcomed the Irish province as the only unbeaten team in the PRO12 and a 3-3 scoreline at the break left Connacht in a promising position to change that.
Hassler hit them after the break with a superb score and Martin Roberts soon made it worse, while 21-year-old flyhalf Sam Davies overcame a nervy start from the tee to rack up 16 points.
Eoin McKeon went over late on for the visitors but it was no more than a consolation as Connacht's losing streak at the Liberty Stadium stretched to ten.
Dominic Ryan grabbed a pair of tries as Leinster extended their unbeaten run at the RDS to 23 with a 33-8 triumph over an injury-plagued Edinburgh side.
Alan Solomons' side came into the contest with an 18-strong injury list and it got worse as the game went on but they rarely looked like troubling the reigning PRO12 champions.
Nikola Matawalu scored the game's only try as in-form Glasgow Warriors maintained their strong start to the PRO12 with a hard-fought 17-9 win over Benetton Treviso.
The Italians remain winless this campaign but they will take much heart from their showing in slippery conditions at Scotstoun as three penalties from Jayden Hayward kept them close throughout.
Matawalu's superb first-half score, plus four penalties from the boot of Peter Horne meant that a much-changed Warriors side never trailed but failed to cut loose against stubborn opposition.
Replacement prop Albert Anae saw red late on for the visitors for a punch and after just missing out on a losing bonus point the Italians now must contemplate a 12-match losing run in all competitions.
All of Friday's scores and scorers:
Ospreys 26-11 Connacht
The scorers:
For Ospreys:
Tries: Hassler, Roberts
Cons: Davies 2
Pens: Davies 4
For Connacht:
Try: McKeon
Pens: Donaldson 2
Ospreys: 15 Dan Evans, 14 Jeff Hassler, 13 Andrew Bishop, 12 Josh Matavesi, 11 Tom Grabham, 10 Sam Davies, 9 Martin Roberts, 8 Ieuan Jones, 7 Justin Tipuric, 6 Sam Lewis, 5 Rynier Bernardo, 4 Lloyd Peers (captain), 3 Aaron Jarvis, 2 Sam Parry, 1 Duncan Jones.
Replacements: 16 Scott Otten, 17 Marc, Thomas, 18 Dmitri Arhip, 19 Rory Thornton, 20 Jordan Collier, 21 Tom Habberfield, 22 Ashley Beck, 23 Aisea Natoga.
Connacht: 15 Shane Layden, 14 Niyi Adeolokun, 13 Bundee Aki, 12 Craig Ronaldson, 11 Matt Healy, 10 Jack Carty, 9 Kieran Marmion, 8 George Naoupu, 7 Eoin McKeon, 6 John Muldoon (captain), 5 Quinn Roux, 4 Mick Kearney, 3 Rodney Ah You, 2 Jason Harris-Wright, 1 Denis Buckley.
Replacements: 16 Dave Heffernan, 17 Jamie Dever, 18 JP Cooney, 19 Andrew Browne, 20 Willie Faloon, 21 Ian Porter, 22 Dave McSharry, 23 Darragh Leader.
Referee: John Lacey
Assistant Referees: Ben Whitehouse, Martyn Lewis
TMO: Paul Adams
Leinster 33-8 Edinburgh
The scorers:
For Leinster:
Tries: Ryan 2, Conan, Marshall, M McGrath
Cons: Gopperth 4
For Edinburgh:
Try: Leonardi
Pen: Heathcote
Leinster: 15 Zane Kirchner, 14 Darragh Fanning, 13 Ben Te'o, 12 Noel Reid, 11 Luke Fitzgerald, 10 Jimmy Gopperth, 9 Luke McGrath, 8 Jack Conan, 7 Dominic Ryan, 6 Kevin McLaughlin (captain), 5 Kane Douglas, 4 Tom Denton, 3 Tadhg Furlong, 2 Richardt Strauss, 1 Michael Bent.
Replacements: 16 Bryan Byrne, 17 Ed Byrne, 18 Peter Dooley, 19 Ben Marshall, 20 Dan Leavy, 21 Isaac Boss, 22 Steve Crosbie, 23 Mick McGrath.
Edinburgh: 15 Nick McLennan, 14 Dougie Fife, 13 Joaquin Dominguez, 12 Andries Strauss (captain), 11 Tim Visser, 10 Tom Heathcote, 9 Sam Hidalgo-Clyne, 8 David Denton, 7 Tomas Leonardi, 6 Magnus Bradbury, 5 Jack Turley, 4 Ben Toolie, 3 Willem Nel, 2 James Hilterbrand, 1 Allan Dell.
Replacements: 16 Jake Kerr, 17 Rory Sutherland, 18 John Andres, 19 Jamie Ritchie, 20 George Turner, 21 Sean Kennedy, 22 Greig Tonks, 23 Jack Cuthbert.
Referee: Nigel Owens (Wales)
Assistant Referees: David Wilkinson (Ireland), Stuart Douglas (Ireland)
TMO: Kevin Beggs (Ireland)
Glasgow Warriors 17-9 Treviso
The scorers:
For Glasgow Warriors:
Try: Matawalu
Pens: Horne 4
For Treviso:
Pens: Hayward 3
Glasgow Warriors: 15 Peter Murchie, 14 Lee Jones, 13 Richie Vernon, 12 James Downey, 11 DTH van der Merwe, 10 Peter Horne, 9 Niko Matawalu, 8 Ryan Wilson, 7 Chris Fusaro, 6 Josh Strauss (captain), 5 Leone Nakarawa, 4 Tom Ryder, 3 Rossouw de Klerk, 2 Pat MacArthur, 1 Ryan Grant.
Replacements: 16 Dougie Hall, 17 Alex Allan, 18 Zander Fagerson, 19 James Eddie, 20 Will Bordill, 21 Murray McConnell, 22 Connor Braid, 23 Rory Hughes.
Treviso: 15 Jayden Hayward, 14 Simone Ragusi, 13 Michele Campagnaro, 12 Enrico Bacchin, 11 Ludovico Nitoglia, 10 Sam Christie, 9 Alberto Lucchese, 8 Francesco Minto, 7 Alessandro Zanni (captain), 6 Simone Favaro, 5 Corniel Van Zyl, 4 Tomas Vallejos, 3 Salesi Manu, 2 Davide Giazzon, 1 Matteo Zanusso.
Replacements: 16 Amar Kudin, 17 Albert Anae, 18 Rupert Harden, 19 Mat Luamanu, 20 Marco Lazzaroni, 21 Marco Barbini, 22 Luca Morisi, 23 James Ambrosini.
Referee: Ian Davies
Assistant Referees: Neil Paterson, Lloyd Linton