The Poppies twice led at Evo-Stik Northern Premier League Division One South side Leek Town, only to be pegged back on both occasions.
With the game in the balance at 2-2, Law threw on new signing Aaron O’Connor from the bench and he missed a late penalty before making amends with a stoppage-time winner as the Poppies claimed a 3-2 success.
That made it two wins in a row for Law’s men following last Monday’s Evo-Stik Southern League Premier Division victory at King’s Lynn.
The Poppies boss was generally pleased with the way his team performed and he was delighted to see O’Connor grab what he described as “a fantastic goal”.
“We played really well,” the Kettering manager said.
“We shifted the ball well, we dominated possession and it would just be nice if we could make things a bit more comfortable for ourselves. We seem to enjoy doing things the hard way.
“When you play in the FA Cup, it’s always a case that anything could happen but the target for us was to ensure we were in the hat and that’s what we have done.
“They scored a free-kick just before half-time but we dominated the second half, got in front again and then they have hit us on the counter-attack and once they had equalised for the second time, the main aim for us was to make sure we were in tomorrow’s draw.
“Aaron has come on and he has been unable to solve our penalty hoodoo but he has more than made up for it.
“But it really was a fantastic goal from Aaron. He has got between their central defenders and I don’t think the keeper quite realised where the ball had gone because it was such a powerful strike.
“Having said that, all three goals were good. It was a fine 30-yard strike from Nathan and the build-up play before Rene’s header was great.
“We are a team that has been fighting with confidence but the players are giving me absolutely everything and they can be very happy with what they have done in the last two games.”