The Spaniard, playing his 229th event, had previously been a runner-up on six occasions, including two second-place finishes in consecutive weeks last month, but held his nerve on the formidable Red Course at Royal Golf Dar Es Salam to claim the coveted bejeweled dagger.
The 32-year-old, who earned his European Tour card in 2011 after graduating from the European Challenge Tour, started the final round one stroke behind South African Erik van Rooyen, who was also chasing a first win on the European Tour.
Campillo fell off the pace with two bogeys on his first three holes, but pulled one back with a birdie on the eighth hole. He then moved back up the leaderboard with a birdie the 11th and claimed the outright lead with another gain on the 16th hole.
His fourth birdie of the day followed on the 17th and he took a two-stroke lead down the 72nd hole. He pulled his drive off the par-five 18th tee, finding a bunker, but he recovered and parred the final hole to finish on nine under par two strokes ahead of van Rooyen and American pair Sean Crocker and Julian Suri.
American David Lipsky finished solo fifth on five under par, while Scotland’s Grant Forrest and Japan’s Masahiro Kawamura shared sixth place.
Speaking after his win, Campillo said: “It’s hard to describe. It’s been a long road. Grateful, but it’s been way too long. Way too many hours of work since I was a boy to today. I’m just proud that I can say I’m a winner on The European Tour.
”I just love the game. I love competing. Most people say, maybe I’m not a winner, but I was when I was an amateur. It was a matter of time. I think I proved it today. I love winning, I guess, and I finally did it, so I’m quite happy now. Hopefully I can win more from now.”