The 15th seeded duo on Saturday beat the Bryan twins 6-4, 6-7 (6), 6-3, denying the fifth seeds' 17th major trophy, reports Xinhua.
With another Spaniard Garbine Muguruza upsetting defending champion Serena Williams to lift her maiden Grand Slam title on the same court earlier in the afternoon, the day was stubbed 'Spain Special'.
Feliciano and Marc, who're not related to each other, broke their opponents in the first game before wrapping up the first set.
The Bryans, seeking a third title of the clay-court major following victories in 2003 and 2013, forced a tiebreaker in the second set before Feliciano sealed the win with an ace.
In contrary of the Bryan brothers, the most successful pairing of all time, the Spanish duo just teamed up with Olympics in mind since the Australian Open in January.
"You can't imagine what it means to win a Grand Slam for the first time, against the best players in the sport," Feliciano Lopez said.
"Winning a Grand Slam is something amazing, and I didn't have a Grand Slam victory on my resume," said Marc.