Goals from Oliver Hawkins and Rhys Oates settled a match of two halves, which Crawley looked favourite to win after James Tilley's wonder-strike levelled the scoring moments after the restart. Click here to see how we rated the players
Francomb said it was a game of fine margins but rued a lack of cutting edge in front of goal.
"The first half was tough against the wind," he said. "It was disappointing to let in a goal but we kept it at 1-0.
"We came out in the second-half and started really well. We got a good goal and were on top for most of the second half.
"I don't remember them having too many entries in our box other than the goal. It just seems like one of them sucker punch kinds of games it was similar on Tuesday night [against Newport County].
"You're scratching your head to how you've ended up drawing that game Tuesday night and losing today. On the balance of play, we should be getting two wins."
Francomb said the result was 'tough to take' but the Reds 'have still got to do better'.
He said: "At the end of the day, if you're not making it count at one end and then giving it away at the other end, that's football.
"The performances haven't been bad the last two games at home.
"They had two shots on target all game. I don't know how we've had but it felt like we were the team in the ascendency the whole second half.
"We thought we were the only team who would go on and get the second goal. But once chance and it's in the back of our net. It's absolutely gutting."
Crawley now have a ten-day break before their next game away at Walsall on Tuesday, December 7.
Francomb said the break will be good for the players 'who aren't quite close to fitness' but, after defeat, he and his teammates will want to 'put it right as soon as possible'.
When asked what they will focus on during the hiatus, Francomb said: "When we lost five on the bounce, the performances weren't there. We were at sixes and sevens.
"The last two games, our performances have been better and more solid.
"It's just a case of trying to pick ourselves as a group and going again. That's the only way we are going to get out of the position we're in."
The latest defeat leaves Crawley in 19th place, six points clear of the relegation zone with a game in hand.
"You don't want to be looking over your shoulders," Francomb said.
"I haven't checked the table yet but I don't think it looks great at the moment.
"We're not in it [the relegation zone] but we are very close. It's down to us to get ourselves out of it."