His international team mate Brad Barritt also found himself on the score sheet, as Charlie Hodgson added 17 points with the boot - making him the first player to pass the 2,000 point mark in the Aviva Premiership.
Ashton, having moved south from Northampton, produced two trademark finishes - linking well with Joel Tomkins, another Wigan convert - in a busy afternoon that saw the winger shown a yellow card for a barge on Steve Shingler.
The ruthless display by 2011 champions couldn't however live up to the drama of Wasps against Quins which preceded it.
A double for Wasps' Christian Wade and try for fellow England Saxons wide-man Tom Varndell proved to be not quite enough as Harlequins ran down a 27-point deficit to pull off an astonishing 42-40 victory.
After narrowly escaping relegation last year Dai Young's Wasps side looked much improved, causing Quins real problems with their pace out wide - however the defending champions demonstrated the belief and ability that won them their first Premiership title four months previously.
England captain Chris Robshaw led the fight back as they opened up Wasps' defence with a series of sharp off-loads - with England full-back Mike Brown twice the beneficiary with Tom Williams also crossing.
It was left to talismanic fly-half Nick Evans to seal the comeback, slotting a penalty with two minutes on the clock to claim an epic victory.
In another tense opening day match-up, Olly Barkley edged a kicking duel with Worcester's Andy Goode, kicking all of Bath's points in a 24-23 win at Sixways.
Gary Gold, in his first competitive game at the helm for Bath, handed a debut to league convert Kyle Eastmond, in a match that proved to be a real nail-biter, with the lead changing three times in the last ten minutes.
Goode was faultless with the boot early on - kicking four penalties inside the opening 15 minutes - but the Bath fly-half, wearing the ten shirt for the first time since 2010, kept his side in touch before holding his nerve to kick the winning points with the last play of the game.
Elsewhere, another former England international fly-half, Danny Cipriani, had a less enjoyable afternoon on his return to Premiership rugby, as he made his debut off the bench for Sale Sharks in an emphatic 43-6 defeat by Exeter.
Cipriani was called into action on 30 minutes after an injury to Sam Tuitupou, but was powerless to the West Country side.
Five Chiefs players crossed for six tries at Sandy Park - including England new-boy Tom Johnson - with Rob Baxter's side cutting loose in the second half after going in just 14-3 ahead at the break.