The world No. 1 followed up last week's win over his fellow Spaniard at the Monte Carlo Masters, claiming his sixth Barcelona championship and his 31st on clay -- third-most all time since the beginning of the Open Era in 1968.
Nadal now trails Guillermo Vilas with 45 and Thomas Muster's 40 in career clay-court titles.
He also improved to 45-15 for his career in championship matches and to 13-4 lifetime against Ferrer.
Ferrer, meanwhile, came up a bit short in his bid for his third crown of the year following wins in Auckland and Acapulco, falling to 11-12 all time in finals.