FINAL LEADERBOARD:
(GB unless stated)
-7 P Martin-Benavides (Sp)
-6 R Jacquelin
-3 C Schwartzel (SA), D Griffiths, M Kaymer (Ger), G Storm
Selected others:
-2 A Forsyth, A Oldcorn
Pablo Martin-Benavides made European Tour history by becoming the first amateur to win a tour title.
The 20-year-old Spaniard shot a closing three-under-par 68 to finish one stroke clear of France's Raphael Jacquelin and win the Portuguese Open on seven under.
Jacquelin had the consolation of taking the 141,157 euro (£96,000) first prize, and Martin plans to remain amateur despite missing out on the money.
"It doesn't even cross my mind to turn pro," said Martin.
"I've already thought about it. I've got to play with Oklahoma [State University].
"They've been giving me so many things and it does not enter my mind right now."
Martin has already won the Jack Nicklaus award as the top college player in the States and will lead the amateur world rankings after this result.
Victory earns him an exemption until the end of 2009, but if he delays becoming pro longer than two weeks he will only be able to accept five more invitations in Europe this year.
Just five weeks after making the halfway cut at a US Tour event in Mexico, Martin took full advantage of the absence of Europe's leading lights, all away preparing for the Masters.
Overnight pacesetters Alex Noren and Ross McGowan both shot 76 to fall out of the reckoning.
Jacquelin ran Martin close by birdying the last two holes to move within a stroke, but the amateur held his nerve for victory.
Joint third were English pair Graeme Storm and David Griffiths, South African Charl Schwartzel and German Martin Kaymer.
The last amateur to win a professional event in Europe was Ireland's Dr David Sheehan at the 1962 Jeyes Tournament at Royal Dublin, but that came before the formation of the European Tour.
Phil Mickelson was the last player to do it on the US Tour at the 1991 Tucson Open.