Cejka was one stroke off the overnight lead but six birdies against two bogeys saw the German reach ten under overall with 36 holes to play.
Joint overnight leader Rory Sabbatini was second on nine under alongside Chris Tidland, who had to complete his first round this morning after play was suspended on day one due to darkness.
Omar Uresti, who was alongside Sabbatini on seven under after round one, fired a level par 72 to be one of six players in a tie for fourth on seven under overall.
Cejka was level par through nine holes after bogeys on holes two and seven and birdies on holes five and eight.
Three successive birdies from the tenth propelled Cejka up the leaderboard and a birdie three on the 17th saw him take the sole lead.
Tidland completed a six under 66 this morning before carding a 69 in his second round, featuring seven birdies and four bogeys.
Sabbatini carded four birdies against two bogeys.
Robert Garrigus, Steve Elkington, Woody Austin, John Mallinger and Brian Davis were alongside Uresti three strokes off the lead, while four players were on six under and six on five under.