The Saints boss was delighted as his side hit back from conceding a goal just after the half-hour mark as Christian Benteke fired the Eagles in front at St Mary’s.
Nathan Redmond equalised right on half time, before Maya Yoshida and James Ward-Prowse struck two goals in as many minutes to steal Saints a late victory.
Long missed three clear-cut opportunities on the night to make the scoreline even more comfortable for the Saints, but Puel had no complaints about the Republic of Ireland international’s attitude.
He said: “I kept going with Shane Long because I wanted him to get the reward of a goal for all his hard work.
“He did some fantastic work for the team.”
On the win which moves the Saints up to ninth on 37 points, the Frenchman added: “I’m happy because our players kept on going and found a solution at the end. I’m happy with the squad, and the quality and the result.
“We were physical and strong and it was important against this team.”
Palace boss Sam Allardyce bemoaned the assistant referee for refusing to flag Steven Davis’ heavy challenge on Wilfried Zaha in the build-up to Saints’ first goal.
Puel also admitted it could have been a foul, but insisted his side could have had three penalties in the first half alone.
“Perhaps, but if we can see that then I think we can have three penalties in the first half,” added Puel.
“If we start to see fault or no fault then that can do other things also for us.”
April 6, 2017