Only 47 players had completed their second rounds on Friday when play was initially called to halt with a severe weather warning in effect.
Nearly four and a half hours later, play was called for the day after more than 2.5 inches of rain had fallen at the Avondale course near New Orleans, filling the majority of bunkers with water.
Play was set to resume on Saturday, weather permitting, with Davis and Owen having advanced to seven under par for the week alongside Cejka, American veteran Lee Janzen and first round leader Jason Bohn, who was yet to get his second round under way following an opening 65.
Davis, runner-up last week to Jim Furyk at the Verizon Heritage having called a penalty on himself during a sudden death play-off, continued his good form with a six under par 66 at the 7,340 yard course in Avondale, near New Orleans.
After an opening round of 71 Davis went birdie, bogey, birdie, par, bogey to start his round on the back nine.
He then took four at the par five 18th to start a ten hole run that saw seven birdies for the 35 year old Londoner, chasing his first win in the US and a first title since the 2004 ANZ Championship on The European Tour.
"Yesterday was tough, the wind was up and, with the hangover of last week, anything under par would have been good yesterday." Davis said.
"I holed a putt at the last for one under and was really happy with that.
"I went out today and nothing was really happening, and then it just caught fire. I hit some close shots, made a couple of good putts and had a great back nine."
Owen had opened with a 67 and was bogey free in his second round when the hooter sounded with his score two under for the day.
Janzen had already carded a bogey free 66 while Cejka's 67 was marred only by a bogey at the par three 17th, his penultimate hole.
One shot back on the early second round leaders and in the clubhouse was Australia's Greg Chalmers, who shot a 68 that included an eagle at the par five 11th.
His compatriot Jarrod Lyle was six under after 14 holes, four under for his round and with two eagles, three birdies and three bogeys already on his card.
Also at six under was former Open Championship winner David Duval, chasing a 14th career victory and his first since lifting The Claret Jug at Lytham and St Annes in 2001. Duval, who was a runner up earlier in the season at Pebble Beach and shot an opening 68 in New Orleans, had reached the fourth with birdies at the second and third holes before his round was interrupted.
Argentina's Andres Romero, the 2008 champion, moved up the leaderboard with a second round 68 to reach halfway at four under alongside US Ryder Cup player Boo Weekley, who had a 70 and Korean K J Choi, who shot 72.
Sweden's Daniel Chopra (70) and England's Justin Rose were at two under, Rose's level par 72 including four birdies, two bogeys and a double bogey.
Sergio Garcia of Spain put a poor first round 73 behind him to shoot a 69 and put himself inside the projected cut line, which stood at one under when play was suspended.