City led 2-0 at one stage when they welcome their higher-division Isthmian League rivals to Oaklands Park on Tuesday in the Velocity Trophy.
A ten-minute, three-goal burst by the Kent visitors turned the game on its head and they ended up going through. But for Rutherford, the fact a fairly experimental City line-up had pushed a strong Invicta team so hard showed how far his squad had come recently.
The grand effort in the cup came three days after an early Ryan Davidson goal earned Chi City a 1-0 home win over Three Bridges in the Isthmian south-east division.
That win sets up Rutherford and Co for another two Sussex derbies in the league – they go to Whitehawk this Saturday then welcome high-flyers Haywards Heath to Oaklands seven days later.
Rutherford said: “We picked a team to play Folkestone that had six under-23s in it and included a few players who had not had many minutes later.
“We thought Folkestone would be resting people as well but they put out pretty much their first-choice team, so we were thinking ‘what’s going to happen here?’
“But it turned out to be a very good test for us and for the first 45 minutes we were superb and went 2-0 up.
“As the game went on we didn’t have the same energy and they scored three in ten minutes. Overall we have to be pleased with how we acquitted ourselves. It’s great experience for some of our younger players to be facing opposition from the step above.”
Rutherford was pleased with the weekend’s league win – which left them ninth and put behind them a couple of poor results which saw them take just one point from clashes with Lancing and East Grinstead.
Rutherford said: “We were poor in those two games for whatever reason and needed to improve, which we did on Saturday. Our first aim this season was to stay up and now we’re in the sort of league position where we can think about whether a play-off bid might be possible.”