The Brazilian bantamweight swarmed Pickett early at UFC 204 before finishing the veteran Brit on the ground at Manchester Arena. Alcantara got his 13th career submission win at 1:59 of the opening round.
Alcantara pressured Pickett early, keeping him off balance with a variety of strikes. He dropped Pickett and delivered ground-and-pound punishment.
From there, Alcantara positioned into an armbar. While Pickett was able to roll with it, when they got to the other side, Alcantara transitioned into a triangle choke and got the tapout.
"I was training for this fight hard than I ever have," said Alcantara (34-7, 1 NC) who won for the second time in his past three fights and fifth in his past seven. "I was focused. I wanted to show everyone I am a black belt in jiu-jitsu."
The 38-year-old Pickett (25-12) lost for the fourth time in his past five fights.