Hazel opened his scoring account for the Pilgrims with a brilliant long-range effort two minutes before half-time.
Sotona sealed the deal three minutes after the break when he converted from the spot after Hazel had been fouled by Josh Coulson.
United boss Ian Culverhouse had made one change ahead of kick-off, with Jai Rowe replacing the injured Zak Mills.
The Pilgrims made much of the early running against their struggling opponents from Norfolk, who they had defeated 2-1 at the Walks Stadium on Boxing Day.
Sam Smart was denied by a flying Paul Jones save, while Hazel and Sotona were both thwarted by brave Lynn blocks on the follow-up.
Kyle Callan-McFadden's header dropped wide for the visitors following Ben Stephens' free-kick delivery, while a Brad Nicholson header flew wide at the other end.
Jimmy Knowles broke quickly in the 43rd minute before teeing up HAZEL to arrow home a fierce left-footer off the inside of Jones' right-hand post.
Hazel was subsequently fouled by Josh Coulson after the break and SOTONA beat Jones with a low penalty three minutes into the half.
Jordan Richards, fresh from his goal in the reverse fixture, cracked a long-ranger narrowly wide as United sought a killer third, but Michael Bostwick produced a superb late block to deny Stephens, with Coulson heading wide from the resultant corner.
Boston (4-4-2): Aaron Chapman; Jai Rowe, Michael Bostwick, Tom Leak, Brad Nicholson; Sam Smart (Keaton Ward 73), Jordan Richards, Keziah Martin, Deji Sotona (Michael Gyasi 88); Jimmy Knowles, Jacob Hazel (Kelsey Mooney 83). Subs (not used): Dylan Hill, Jake Lovelace (gk).
King's Lynn (3-4-1-2): Paul Jones; Adam Crowther, Josh Coulson, Kyle Callan-McFadden; Cameron Hargreaves, George Morrison, Tommy Hughes (Cameron Forde-Brown 76), Gabriel Rogers (Aaron Powell 46); Ben Stephens; Bartosz Cybulski, Jordan Ponticelli (Kian Ronan 46). Subs (not used): Josh Barrett, Tommy Dixon-Hodge (gk).
Referee: Lee Hible.
Attendance: 2,670 (296 visitors).
PIC: Russell Dossett.