Spurs faced being six points off the pace until Eriksen's long-range strike with 12 minutes remaining at Selhurst Park secured a 1-0 triumph and ensured the gap to leaders Chelsea is just four.
It was Denmark midfielder Eriksen's eighth Premier League goal of the season, and he acknowledged it could be the most important.
"Yes, it was a very big goal. We showed we're still in it," he said.
"We have to focus on ourselves, and of course Chelsea have to lose some points, but that was our chance to keep going and we took it.
"That result gives us a confidence boost for the last five games. We have to keep going, focus on ourselves and see where it ends."
They desperately needed a pick-me-up in south London to keep their campaign alive, and that was never going to be easy against an in-form Palace side looking to add Spurs to the scalps of Chelsea, Arsenal and Liverpool this month alone.
It was exactly the sort of match in which Mauricio Pochettino's men may have dropped points last season, but they are a tougher proposition this term and stretched their winning run to eight Premier League matches.
The result marked the first time Tottenham have managed eight straight league victories since 1960.
"It was a very tough game and we fought well, the whole team, the subs as well," Eriksen added.
"Everyone dug in and luckily we took the chance we had.
"After we scored we showed a lot of maturity, we showed we're capable of keeping the ball which a few years ago maybe we wouldn't have done.
"We did that and played it well. We have to do that to win things in the future.
"We're on a good run, we have a lot of confidence and we're giving it our all. We have a chance and that's these last five games."