Rob Baxter’s side moved up to second in the Aviva Premiership standings, just two points behind the Saints, following their 24-18 victory at Franklin’s Gardens.
A powerful first half display from the visitors saw them storm into a 21-6 lead at the break thanks to converted tries from Luke Cowan-Dickie and Thomas Waldrom (2).
Fly-half Gareth Steenson slotted the extras to all three scores, as well as adding a second half penalty to ensure Exeter of their fifth league win in seven starts.
For Francis, a summer signing from Championship side London Scottish, it has certainly been a dream start to life at Sandy Park. The 22-year-old has been a virtual ever-present in the Chiefs match-day squad already this term - and his powerful scrummaging has already won him rave reviews.
Against the Saints on Friday, Francis was part of a Chiefs side who quickly set about dismantling last season’s Premiership champions on their own turf.
Exeter’s superb first half showing laid the foundations for their success, although it was in defence in the second period where they were equally as good, repelling a late onslaught from Jim Mallinder’s men.
“We said from the start the battle was going to be up front,” said Francis. “We knew we had to take them on - not settle for par - and get an early foot hold on the game. I thought we did that really well and that set the platform for us.”
Indeed, it took the Chiefs barely two minutes to make their mark as Cowan-Dickie, a late call-up at hooker for the injured Jack Yeandle, stole over for Exeter’s opening try from a driving maul.
No.8 Waldrom added further tries before the break - including an intercept that saw him race over half the length of the pitch to score - before Steenson landing a telling penalty early in the second half to put the Chiefs further clear.
“The boys really showed their heart in the end,” added Francis. “We knew coming here would be tough, but we gave everything in that first 40 minutes. We got ourselves a good lead and then we were able to hang in there during the second half.
“This result, I think, could define our season. Some people had said we had an easy start to the season and that these next three games would really test us. As we know, there are no easy games at this level, but we’ve got another good win under out belt and hopefully we can continue to stay in the top four.”
With back-to-back encounters against Wasps and Saracens next up, Francis says it’s vital that the Chiefs look to make the most of home comforts during the next fortnight.
“Sandy Park is like a bit of a fortress for us, so hopefully we can carry this form into those two games,” he continued. “We’ve got an eight-day turnaround from this game, so it’s important we get freshened up and back out there for what will be a tough game against Wasps next weekend.”