Ebanks-Blake's shot on the turn midway through the second half was the one moment of real class in a scrappy affair.
Hull, under the caretaker management of former Derby boss Phil Brown for the first time, proved obdurate opponents until Ebanks-Blake cushioned Lilain Nalis' pass, spun round and turned Damien Delaney, and whipped a shot past goalkeeper Boaz Myhill from the edge of the penalty area.
The victory was overshadowed by a horror injury to Argyle skipper Paul Wotton, who twisted his knee in falling awkwardly just before half-time.
The midfielder, who has played more than 350 games for his home-town club, is believed to have damaged cruciate and medial ligaments and faces a lengthy spell on the sidelines.
He was replaced by 16-year-old Dan Gosling, who became the first Argyle player born in the 1990s to represent the club.
With Hasney Aljofree and David Norris suspended and Nick Chadwick, Paul Connolly and Lee Hodges injured, Argyle manager Ian Holloway's line-up was as experimental as Brown's first selection following Phil Parkinson's dismissal earlier in the week.
The lively Craig Fagan caused concern when he broke behind the Argyle backline, but a heavy touch and Luke McCormick's swiftness from his goal-line saw off the menace.
Argyle's first flowing move of the game came after an hour and it nearly paid dividends, with Barry Hayles finally providing a cross from which substitute Akos Buzsaky's shot was cleared off the line by Danny Coles before Gosling just failed to get to a rebound and become Argyle's youngest ever scorer.
The Tigers' spirit was then broken with the lovely piece of individual skill from Ebanks-Blake, who beat the otherwise impassable Myhill for pace.
The Pilgrims looked for the settler and Luke Summerfield nearly got it when he unleashed a 30-yard drive that whistled past Myhill's post.