His closest pursuers and playing partners, Ian Woosnam and Maarten Lafeber, both carded over-par rounds as they faltered down the stretch.
Cejka, whose last victory came in 1995, had a solid if not spectacular day with four birdies and a lone bogey to finish the tournament at 12-under 272.
I have been waiting since 1995 and it has been seven long years, he said. It was hard at times but I put in a lot of hard work in that time and stayed patient when things were not going so well, so I am very happy right now.'
More from Alex Cejka on his win.
A key birdie at the 10th by Cejka moved him a shot clear of a small cluster of players that were threatening the German. He would not relinquish the lead.
I didnt have anything else in mind today apart from trying to make good shot after good shot, hole after hole. I needed a bit of luck as well, all winners do, and I got that, but I also tried not to make any stupid mistakes and it worked to perfection.
Carlos Rodiles shot one of the days best rounds, 66, and ended the tournament all alone in second place. The Spaniard, whos previous best finish was a fourth-place showing at the Volvo PGA Championship, strung together five birdies in the middle of his round and added another at the 15th to edge out Jean-Frances Lucquin and Angel Cabrera.
Lucquin, who also had a final-round 66, had seven birdies on Sunday two of them coming on the 16th and 17th, but took a bogey on the par-3 18th to fall out of second and into a tie for third.
Cabrera, the winner at the Benson and Hedges earlier in the year, enjoyed a bogey-free 67 for a four-day 9-under-par 275.
Sergio Garcia ended the tournament tied for fifth with seven other players at 8-under-par. Garcia, who is sixth on the European Order of Merit despite playing in only 10 events, had a pair of early bogeys but rebounded with four birdies to record his amazing ninth top-10 finish in his 10 starts.
Also in that group was Frances own Thomas Levet, the runner-up at this years British Open. Levet posted four birdies on the front nine that got the locals going but couldnt come up with any on the back side.
The best round of the day, and tournament, was produced by Welshman Mark Pilkington. His 9-under-par 62 moved him from 61st up into a tie for 13th.
Full-field scores from the Trophee Lancome