The 32-year-old was forced to work hard to overcome a stubborn Falla who refused to roll over against his illustrious opponent.
"I've left a little bit of my heart there," Federer said after his seventh victory in nine Halle finals.
"My big goal for the week was to collect the title, play good tennis and have fun. I've done that."
The 17-times grand slam champion served for the first set at 5-3 only to get broken by Falla, who was chasing his first ATP title.
With the tiebreak locked at 2-2 Federer's class told as he stepped up the tempo to reel off five points to take the set.
That momentum continued into the second set with the Swiss breaking Falla in his first service game but he once again failed to capitalise and was immediately broken back.
The players headed into a second tiebreak and after Federer romped to a 3-0 lead, his 69th-ranked opponent faded away to suffer his seventh defeat in as many meetings with the Swiss.
"He's the king of kings of tiebreaks," Falla said. "Overall I played very well throughout the whole week and I want to keep it up."
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