The 26-year-old from San Pedro de Alcántara, near Malaga, birdied the last two holes to finish a stroke clear of Hernández and Wales’ Amy Boulden.
ACT’s Nikki Campbell and Bree Arthur were the leading Australians in a share of 22nd position at two-over-par. Arthur posted rounds of 69, 69, 73 and 71, while Campbell had rounds of 67, 70, 76 and 69.
Welsh Ladies European Tour rookie Boulden, playing in the penultimate group, set the target at 10 under par and watched as Hernández missed her birdie putt before Muñoz expertly sent her ball into the middle of the hole from three metres.
“I just love this place, you know. I’ve been playing well all week but putts weren’t dropping and when it came to the last two I knew I needed at least one birdie to go to the play-off,” said Muñoz.
“When I dropped that one at 17 I thought I had a really good chance and on 18 too, I just focused on hitting a good putt. Putts haven’t dropped all week so I guess it was my time and I’m just really happy. On 11, 12, 13 and 14 I made pretty good par putts and that kept me going and then three birdies in the last four.”
England’s Florentyna Parker finished in fourth place on nine-under-par while French rookie professional Isabelle Boineau from Marseille earned a career best finish of fifth place.
Solheim Cup stars Charley Hull and Carlota Ciganda tied for sixth, while Frenchwoman Gwladys Nocera was eighth. Swiss amateur Albane Valenzuela, 16, from Geneva finished ninth on four-under-par and local player Anne-Lise Caudal from St Jean de Luz, England’s Hannah Burke and Sweden’s Sophie Gustafson ended in a share of 10th on three under par.
New Zealand’s Cathryn Bristow finished in a share of 48th place at 8-over-par, while NSW’s Nikki Garrett had a disappointing final round of 76 to fall back into a share of 52nd position after signing for a 76 on the par 70 layout.
Campbell continues to lead the Australians on the ISPS Handa Order of Merit following the Lacoste Ladies Open de France. Campbell is fifth with Euro 138,206. NSW Rebecca Artis, who has been playing mainly on the Symetra Tour in America, is the next best placed. She is 32nd with just under Euro 55,000.
Sarah Kemp is in 39th position, while Stephanie Na is 49th. Nikki Garrett has performed well since returning from a break and is now in the top 60 in 58th place, while Bree Arthur is 69th. Whitney Hillier is 80th and with the top 80 securing a full card for 2015, she will be looking for some strong performances to secure her card for 2015.
The likes of Alison Whitaker and Adriana Brent will have to perform well in coming events to move up the money list and secure full card for next year.