"It's basically what I work for," the 26-year-old said after his first European Tour victory. "I'm very grateful it finally came."
Del Rey shot his third straight 66 for a 22-under-par total of 266.
Englishman Marcus Armitage, who started the day in second, carded 68 to stay there. He was three clear of Spaniard David Puig, who finished with a 65.
Del Rey joined the tour at the start of the 2023 season and recorded a third-place in his first event before spending two years in the middle of the pack.
"I got to a point last year where I wasn't having that much fun on the golf course. Playing for 20th or 30th place wasn't that meaningful," he said.
"I just worked really hard since then I didn't want to be in that position much longer."
If Del Rey felt the pressure starting the last round with a two-shot lead, it did not show.
He opened with a birdie and then hit the flag at the par-4 second to set up a tap in for another birdie. After he birdied the fifth, Del Rey was five shots ahead.
Playing partner Armitage cut the lead to three at the turn but Del Rey responded.
He chipped in at 11 to start a run of three birdies that protected his cushion although he had some luck at the 15th when his ball hit a rake which stopped it rolling into a bunker.
Del Rey was bogey-free over the last two rounds.
"Just felt great today, felt very natural and very easy," said Del Rey.
"I always felt I was a great closer of golf tournaments and I wasn't happy that I wasn't in that position for the past couple of years. Not having the chance was rough."