Fish, the top seed, will try to become the first No. 1 seed in the 16-year history of this tournament to take the title when he faces Russian qualifier Evgeny Korolev on Sunday.
Korolev reached his first career final with a 6-1, 7-5 win over Christophe Rochus in the first semifinal.
Fish was facing a break point to go down 4-1 before taking control of the semi.
"I've never seen him play,'' said the American, who served and volleyed Chardy off the court in winning 11 of the last 13 games. "I didn't know any of his patterns, ins and outs.''
Fish was 2-10 in ATP Tour finals, including a loss at San Jose, California this month.
"I played great the second set,'' he said. "Even the game he won I had a game point.''
Korolev was the second consecutive qualifier to secure a final berth at this tournament. Kei Nishikori of Japan won the championship but did not attempt to defend his title this year.
"I'm very happy I won,'' Korolev said. "Every tournament you play you hope to win it. This is the first time I'm in the final.''
The 105th-ranked Korolev was the fourth qualifier to reach the Delray Beach final. Besides Nishikori, Alex Calatrava of Spain was a finalist in 2000 and Andrew Ilie of Australia won in 1998.
"I just know that Nishikori was coming out of the qualis last year and I'll be happy to do the same thing,'' Korolev said.
Korolev, a first cousin of former player Anna Kournikova, was the first Russian to reach the Delray Beach final.
He pummeled 60th-ranked Rochus in the first set with his heavy groundstrokes, particularly off the forehand.
In the second set, Korolev jumped out to a 5-2 lead and served for the match at 5-3. Rochus took advantage of a brief letdown by Korolev to hold serve at love in the eighth game and to break in the ninth game, but couldn't push his way into a third set.
Exclusive: Indonesia - Hosting World Cup Is Not Impossible
Korolev makes first career final at Delray Beach
Korolev makes first career final at Delray Beach
