Toulon thrash Stade Francais
The former England international extended his remarkable scoring run since making the switch to France from Saracens at the start of the season and has now scored 17 tries in the league.
Toulon had a try bonus in the bag by half-time to cement their place in the top six play-off spots.
"It was a clean performance. We had stressed the simple things and the team kept it simple," said Toulon coach Fabien Galthie, who was nonetheless not entirely satisfied.
"We were very effective. At half-time I asked for more intensity but the way the game panned out we weren't able to increase the tempo."
Although Ashton deservedly took the headlines for a typically predatory performance, it was flyhalf Francois Trinh-Duc's soft hands that ran the show.
Trinh-Duc celebrated his recall to the France squad for next weekend's Six Nations clash with Italy by knocking over a fourth minute penalty, before Ashton took over.
Trinh-Duc sent Semi Radradra galloping into a gap with a cleverly delayed pass and the Fijian cross-code convert fed Ashton to dive over in the corner in the seventh minute.
Quick hands after a scrum on 28 minutes gave Ashton the space to arc around Jonathan Danty and score his second try, with Trinh-Duc converting this time.
And two minutes before half-time Ashton completed his treble.
Another perfectly-weighted pass form Trinh-Duc sent Radradra scything through a hole and when he was hauled down a couple of metres short of the line, fellow wing Ashton arrived to catch a pop pass from the ground and flop over the line.
Trinh-Duc converted again and Toulon went into the break leading 22-0.
The only blip on an otherwise perfect first half was seeing New Zealand international centre Malakai Fekitoa leave the field for a head injury assessment after seemingly being knocked out when tackling Stade midfielder Theo Millet, whose shoulder connected with the All Black's jaw.
On his return after a three-week ban for uttering a homophobic slur, Mathieu Bastareaud – who like Trinh-Duc has been recalled to the France squad – extended Toulon's lead after barging over from close range despite the attentions of three tacklers.
Trinh-Duc converted before making way for Jonathan Wisniewski.
The one-way traffic continued as Ashton took the ball up close to Stade's line and scrumhalf Eric Escande strolled over for the fifth try, with the visitors' defence stretched and disorganised.
The Parisians did get on the scoreboard on 63 minutes with a simple catch-and-drive from a line-out as Laurent Panis crossed.
But Toulon had the last word as Raphael Lakafia bullocked through two tacklers to ground the ball.
"We're disappointed by the score. Toulon deserved it, there's no doubt," said Stade's backs coach Julien Dupuy.
Champions in 2015, his side are fighting for survival this season.
Montpellier stretched their lead at the top with a 43-30 win at Oyonnax. Wing Nemani Nadolo scored two of his team's six tries as Montpellier went six points clear.
Toulouse are also in the play-off spots after an eight-try 52-25 mauling of second-bottom Agen which saw centre Gael Fickou grab three tries and winger Yoann Huget two.