Boss Michael Goode praised “a great achievement” after Deeping Rangers secured second spot.
The Clarets are nine points ahead of third-placed Yaxley – plus a far superior goal-difference – with three league games to go.
They won 4-0 at Oadby Town on Saturday thanks to goals from Scott Coupland, Dan Schiavi (2) and Scott Mooney.
Goode admitted: “We were taking nothing for granted but we wanted to win every game until the end of the season and hit 99 points.
“That would be a great achievement in itself and we have got second place behind Peterborough Sports who are deserved champions.
“We have talked about a poor start to the season as we maybe could have got closer and put on more pressure.
“Anyone who has been involved in this league will know that finishing second can’t be under-estimated.
“It’s a tough league but the way we have played and gone about our business has been brilliant.
“We have been tight at the back with a fantastic record defensively and we’ve scored more than 100 goals.
“We had a slow start and a few poor results along the way in little patches.
It has been a really good league campaign and the type of football we’ve produced in the majority of games has been good to watch.Michael Goode
“On Saturday, we scored a couple of good goals in the first half and then Schiavi scored a superb 25-yard free-kick.
“From that point, we got our substitutes on and we continued to play well.
“We want to keep going until the end of the season by winning more games in the right way.
“It’s a great achievement after the disappointment of last season.
“Although we didn’t start this term particularly well, we knew the quality was there.
“We just needed to turn things around and we worked hard in training.
“It has been a really good league campaign and the type of football we’ve produced in the majority of games has been good to watch.
“At the start of the season, we set our targets – even if we didn’t tell everyone else.
“Every year we’ve got to be looking to reach both local cup finals because you only have to win a few games.
“It was really disappointing last season when we went out of the Lincolnshire FA Senior Trophy to Boston Town. This time, we should be feeling confident and both cup finals start even.”