Marshall conjured up a piece of magic at the first extra hole, the par-5 18th, to see off fellow Englishman Adam Sagar at Al Badia Golf Club.
Two shots in front overnight, Marshall shot a final round 73 to finish eight-under for the tournament and force the playoff after Sagar carded a clubhouse target 68.
Day one leader Younes El Hassani of Morocco was one of four men sharing third on six, joining Sixto Casabona-navarro of Spain, Fredrik Lindblom of Sweden and Chile’s Antonio Costa.
The day, however, belonged to Marshall who picked up a $9,000 cheque alongside the trophy.
“It feels nice to get the job done. I played quite nicely, but my putting wasn’t up to the mark, missed quite a few short ones coming home,” said Marshall.
“I needed to birdie the final hole to win in regulation, but my aggressive approach didn’t pay off. I chipped out of the bunker well, but missed the ensuing putt by a whisker.
“Also, hot and humid conditions made things a bit difficult and then there was the pressure of holding on to the lead.
“I am loving this little run on the MENA Golf Tour. If I can keep the momentum going it will be great.”
Chile’s Matias Calderon upstaged Indian starlet Rayhan Thomas for the leading amateur award, finishing on his own in seventh at five under. Thomas, who won the Dubai Creek Open last week, had to settle for a share of ninth at three under.
“I struggled with my putting in the opening round, but played really well over the next two days. Certainly, proud of my work during the week,” said Calderon.
Morocco’s El Hassani won the MENA Division for professionals while Saudi Arabia’s Othman Almulla took the honours in the amateur category, finishing one shot ahead of his fellow countryman Khalid Attieh.
The MENA Golf Tour travels to the Els Club Dubai next week for the Golf Citizen Classic, starting September 19.