Eichelberger opened with consecutive 5-under 65s for a two-stroke victory over Doug Tewell, still two back after 10 holes when the final round was called off at The Moors Golf Club.
Lanny Wadkins was third, four stokes back at 134. Hubert Green finished at 135, and Tom Jenkins, Dale Douglass and Dana Quigley followed at 136.
Eichelberger had his 12th career hole-in-one in the first round, using a 7-iron on the 185-yard eighth hole.
'That turned out to be the difference,' Eichelberger said. 'I never knew it at the time; first time I've ever had anything like that make a difference.'
It was Eichelberger's sixth Senior Tour victory and he is the seventh different winner this year. At 58, he is the oldest winner since Jim Colbert won the 2001 SBC Senior Classic at 60.
Play was suspended because of lightning at 1:47 p.m. and the final round was canceled about 2 hours later after just over an inch of rain soaked the course.
'There's nowhere to play golf,' said Gene Smith, the Senior Tour's assistant tournament director. 'All of the fairways, front side and back side, were totally under water.'
Eichelberger's victory was worth 218 Charles Schwab Cup points, which brings his total to 256 and moves him into the top 10 in the season-long competition for the $1 million annuity.
Hale Irwin still leads the 2002 Charles Schwab Cup race with 780 points. Quigley earned 60 points for his share of fifth place Sunday and leaped over Tom Kite (606 points) into second place with 624 points. Tewell's second-place finish earned him 128 points and moved him from eighth into the fifth position.
Full-field scores from the Emerald Coast Classic