'This win means a lot to me,' said the 23-year-old Siem. 'My dad and me said that when I'm 24 or 25 then I'm ready to win my first professional tournament. Now I've done it one year too early for him.'
This was Siem's first victory on the European Tour after a final-round 66. Havret and Jacquelin each birdied the 18th in regulation to polish off rounds of 5-under 67 and match Siem at 22-under-par 266, which broke Adam Scott's tournament record from 2001.
After the birdies by the French duo, it was off to the 18th hole, which would be played until there was a winner. This marked the second consecutive year in which an extra session was needed to determine the champion. Last year Mark Foster outdueled five other players to hoist the trophy but in 2004, there were only three competitors.
Siem was in great shape the first time they went around the 18th. He roped an iron to 12 feet with his second shot at the par-5 hole, while Havret missed the green and Jacquelin played his second 40 feet left of the hole. Havret nearly holed his chip from a nasty lie and both players on the green two-putted for birdies, so all three returned to the tee box for the second extra hole.
The second time the trio played 18, Havret drove into a fairway bunker, then laid up in the left rough. Jacquelin missed the green in a bunker with his second but Siem once again left himself less than 20 feet for eagle.
Havret could do no better than par and that would not be enough to stay in the playoff. Jacquelin got up and down from the bunker for the birdie, so Siem had his second chance to win the tournament. But his eagle putt never fell into the cup.
That left Siem and Jacquelin for the third playoff hole, and both players found greenside bunkers with their second shots. Siem landed in a trap to the right of the green and blasted it out to four feet. Jacquelin had a much more difficult shot from behind the green and splashed his third to 15 feet.
Jacquelin's birdie try failed to land in the cup, but he tapped in for par. Siem pumped his fist as his four-footer disappeared into the hole, making him the first first-time winner of the 2004 season.
'I'll be honest, my hands were shaking on that first putt,' admitted Siem, who was chewing gum for the first time on the golf course in order to calm the nerves. 'I thought the first putt was straight and it came from right to left. The second putt was straight but just too slow.'
The Frenchmen were upset but happy at the strong performances.
'It was another good week for me, but I am very disappointed at the end there,' said Jacquelin, who tallied three birdies in his final four holes to join the playoff. 'But I tried, I did well, I did my best. It is a good performance and I will now have to wait for another time.'
'We all want to win, but unfortunately it didn't happen for me,' said Havret. 'But there are a lot more weeks coming up and it is good form for me at the start of the year.'
Soren Hansen, the third-round leader, carded a 3-under 69 and took fourth place at 21-under-par 267. Maarten Lafeber posted a 7-under 65 to come in fifth at minus-18.
James Kingston fired the lowest round of the tournament on Sunday with a 10- under 62. He shared sixth place with Anders Hansen (66), Jarrod Moseley (67), Lee Westwood (68), Craig Lile (70) and last week's South African Airways Open champion, Trevor Immelman (69). The group came in at 16-under-par 272.