Argentina's Cesar Monasterio produced a brilliant up and down from a bunker at his last hole to save par and clinch the Aa St Omer Open title by just one stroke.

The 42-year-old claimed his maiden European Tour victory in northern France after splashing out of the sand beside the 18th green and holing a 10-foot putt.

That enabled him to card a four-under-par 67 and finish on 10 under par - one ahead of South African Martin Maritz, who was playing in the group behind.

"I knew that I had to wait for Martin to putt on the 18th before I knew that I had won, but I didn't think about the play-off," said Monasterio, who won on the Challenge Tour last year.

"I kept the same confidence that I had had since the start of the week and always felt that I could win here. I like the course here, and was confident all week."

Swede Henrik Nystrom, who led by two going into the final round, endured a terrible start to his final round with a double-bogey six, from which he never fully recovered.

In fact it was Maritz, Nystrom's playing partner, who emerged as the main challenger.

Monasterio began with a birdie at the second but soon gave that shot back with a careless bogey on the fifth.

Seemingly incensed at dropping a stroke, the Argentinian went on a great run over the next three holes, picking up a birdie on the sixth, an eagle three on the seventh and another birdie on the eighth to move alongside Maritz at the top of the leaderboard on 10 under par.

Two poor chip shots cost Maritz a stroke at the par-five ninth and with Monasterio carding a birdie at the long 11th and a bogey at the 15th things looked tight going into the last few holes.

The South African then dropped a shot on the 16th to fall one behind Monasterio and he never regained the lost ground as the Argentinian picked up a winner's cheque of £45,000 and a year's exemption - this event being co-sanctioned by the European and Challenge Tours.

Nystrom birdied the last to tie Maritz in second place on nine under par.

Collated final round scores & totals

(Gbr & Irl unless stated, par 71):

274 Cesar Monasterio (Arg) 68 68 71 67

275 Henrik Nystrom (Swe) 69 65 68 73, Martin Maritz (Rsa) 71 67 66 71

276 Juan Parron (Spa) 68 71 69 68, Jean Hugo (Rsa) 67 69 71 69

277 Jamie Little 72 72 64 69, David Dixon 68 71 68 70

278 Paul Dwyer 70 66 73 69, Pedro Linhart (Spa) 71 70 69 68

279 Shaun P Webster 71 68 66 74, Jesus Maria Arruti (Spa) 70 69 71 69, Mikko Ilonen (Fin) 72 68 66 73, Klas Eriksson (Swe) 67 71 68 73, Raymond Russell 70 70 66 73

280 Christian Nilsson (Swe) 76 68 65 71, Fredrik Henge (Swe) 74 71 67 68, Gregory Bourdy (Fra) 73 71 70 66

281 Nicolas Vanhootegem (Bel) 69 69 70 73, Stephen Scahill (Nzl) 72 68 70 71, James Hepworth 71 69 67 74, Rafael Echenique (Arg) 71 72 68 70

282 Chris Gane 69 70 69 74, Sam Walker 72 71 68 71, Lee Slattery 69 70 72 71, Gustavo Rojas (Arg) 73 68 72 69

283 Felipe Aguilar (Chi) 66 73 74 70, Raphael Eyraud (Fra) 71 70 73 69, Neil Cheetham 75 69 68 71, Inder Van Weerelt (Ned) 71 73 71 68, Alessio Bruschi (Ita) 69 73 71 70, Terry Pilkadaris (Aus) 70 70 73 70, Simon Hurd 69 76 66 72

284 Alexandre Rocha (Bra) 71 73 70 70, Ben Willman 71 70 71 72, Denny Lucas 71 72 71 70, Benoit Teilleria (Fra) 71 73 69 71, Kieran Staunton 71 73 71 69

285 Gareth Paddison (Nzl) 72 70 72 71, Mark Pilkington 70 74 73 68, Adrien Mork (Fra) 68 71 72 74, Tom Whitehouse 69 72 71 73, Michele Reale (Ita) 69 73 73 70

286 Jean-Baptiste Gonnet (Fra) 70 73 67 76, Oskar Bergman (Swe) 70 73 71 72, Marco Ruiz (Par) 73 72 70 71, Kyron Sullivan 72 71 75 68, Malcolm MacKenzie 73 70 71 72

287 Graham Fox 74 68 73 72, James Heath 72 70 71 74, Julien Foret (Por) 72 71 73 71, Peter Baker 73 69 73 72, Massimo Scarpa (Ita) 73 71 71 72

288 Joakim Backstrom (Swe) 74 71 70 73, Titch Moore (Rsa) 74 70 72 72, Andre Bossert (Swi) 70 72 71 75, Alexander Noren (Swe) 73 72 71 72, Christian Reimbold (Ger) 72 73 74 69, Alvaro Quiros (Spa) 73 71 75 69

289 Iain Steel (Mal) 73 69 73 74

290 David Drysdale 69 75 73 73, Ilya Goroneskoul (Fra) 72 73 73 72, Jorge Benedetti (Col) 71 68 71 80

291 Alvaro Salto (Spa) 73 72 72 74, Anders Schmidt Hansen (Den) 70 74 75 72, Miguel Carballo (Arg) 73 72 73 73, Cedric Menut (Fra) 68 77 71 75

292 Hennie Otto (Rsa) 73 69 76 74, Roger Chapman 74 69 73 76

294 Johan Axgren (Swe) 72 72 75 75

296 Phil Worthington 73 69 79 75

302 Thomas Nielsen (Den) 73 72 77 80