London Irish handled challenging conditions impressively to win at Harlequins, while champions Saracens were too good for Sale Sharks.
Curtis Rona scored a pair of tries as London Irish secured a 29-15 derby win at Harlequins, while Premiership high-flyers Sale Sharks were brought back down to earth by beleaguered Saracens.
Irish stunned title contenders Northampton Saints last time out and followed that up with a convincing bonus-point victory at The Stoop on Saturday.
Rona laid on the opening try for Matt Rogerson in treacherous conditions and the all-action wing grabbed his first of the afternoon after brilliant work from Ben Meehan.
A Marcus Smith penalty was Quins' only score of the first half and they were 17-3 down at the break after Stephen Myler was on the target from the tee at the other end, having converted both tries.
Alex Dombrandt powered his way over to reduce the deficit, but Rona dotted down again and Ollie Hoskins bagged the bonus point after Cadan Murley helped himself to Quins' second try in west London.
Sale missed the chance to move ahead of Northampton into second spot, going down 36-22 to champions Saracens at Allianz Park after beating leaders Exeter Chiefs in their previous match.
Rhys Carre, Rotimi Segun, Nick Isiekwe and Richard Barrington touched down for Saracens, while fit-again full-back Alex Goode shone in his first Premiership match of the season.
Wasps were beaten 18-9 by fellow strugglers Leicester Tigers at the end of a week that saw director of rugby Dai Young step back from first-team duties, while Bath edged out Worcester Warriors 22-21.
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