And the pair are determined to keep pushing each other all the way in the goal scoring charts.
Horsfall and Guthrie took their combined tally for the season to nine goals at the weekend, as they both notched in the 2-1 Sky Bet League Two win at Harrogate Town.
Horsfall scored his fourth of the campaign as he volleyed home a first-half corner, and at the start of the second half Guthrie took his goal tally to five with a pinpoint header into the bottom corner from a second Mitch Pinnock dead-ball delivery.
That goal means the former Livingston man is now third in the club scoring charts, having netted just two fewer than top scorer Sam Hoskins and one less than Kion Etete.
Horsfall is fourth in that list, and Guthrie admitted: "It's healthy competition we have between us.
"We spoke about it and Fraser said every time I score, I quickly get one back on him so hopefully that can continue!"
Horsfall, who only scored three times in the whole of last season, added: "Jon's pushing me. Every time I get one, he gets one!
"But it's really good and it's healthy to have that competition.
"Every time me and Jon go up for a set-piece, we feel we can be a threat."
And Guthrie is keen to stress that the team's current set-piece excellence is something the players work very hard at.
"The set-piece goals don't come about by fluke," said the 29-year-old.
"It is something we work on and we know with Mitch that the delivery will be on point.
"It's a big part of our game and it's won us a lot of points this season so hopefully that carries on."
The Cobblers have a free week before returning to action with a home clash against Barrow on Saturday.
The Cumbrians claimed their first win in six matches last weekend as they saw off Swindon Town 2-0 at their Holker Street home.
Barrow are managed by former Forest Green Rovers boss Mark Cooper.