Broadbent’s first try was a length of the field interception - from a pass by Jordan Turner - to open the scoring and the second a ‘what happened next?’ effort right at the start of the second half.
Mikey Lewis’ kick off was dropped by Turner and Broadbent gathered to go over just eight seconds after the resumption.
Broadbent was one of three Leeds players in a strong Knights 17 for Castleford man Turner's testimonial game.
Levi Edwards, who had been named in the initial squad, did not feature, but Morgan Gannon and Tom Holroyd were both among the substitutes.
Holroyd put himself about and it was valuable experience for Gannon, at just 17 and with only 13 first team games under his belt.
Other than Turner, the only Tigers man on show was their new signing from Hull KR, George Lawler.
He was sin-binned in the first half for a swinging arm on Jamaica’s full-back James Woodburn-Hall.
Turner, who played at stand-off, was one of only three Super League players in Jamaica’s lineup, along with ex-Leeds man Ashton Golding - who started at hooker - and his Huddersfield Giants teammate Michael Lawrence, at prop.
The rest of the Reggae Warriors’ squad was drawn from the Championship and League One and, as expected, they ran out of gas after competing well early on.
In front of a crowd of 2,250, they were close to opening the scoring when Ross Peltier was held up over the Knights’ line after 15 minutes.
On the next play, Turner fired a pass towards the left wing and Broadbent intercepted and raced the length of the field to break the deadlock, holding off Woodburn-Hall’s valiant chase.
Danny Walker went over from acting-half soon afterwards, following a knock-on by Ben Jones-Bishop under a high kick.
Jones-Bishop made amends with a terrific try-saving tackle on Sam Halsall moments later and, when the Knights were a man down, scored a well-taken try, stepping through the defence from close to the line.
Will Pryce, son of former Great Britain star Leon Pryce, burst on to the Super League scene with Huddersfield midway through this season and is clearly an outstanding talent.
As well as kicking seven goals from eight attempts and setting up a try with a smart kick in the second period, he scored a wonderful solo try almost immediately after Jones-Bishop’s touchdown, Jamaica being unable to do anything about his dazzling footwork.
There was one more try before the break, Aaron Smith nipping through from acting-half on the final play of the half.
Broadbent’s second try on the very next play - albeit 15 minutes later - made it 30-4.
Jamaica held out for another quarter of an hour until Ellis Longstaff touched down from Pryce’s grubber behind the defence and then Matty Ashton scored back-to-back tries to take Knights to 46 points with a quarter of the game remaining.
The first came from a dart out of acting-half by Smith; the second after a break by Lewis and pass from Kai Pearce-Paul.
Hull KR’s Lewis got into his stride in the second half and almost scored a spectacular effort, kicking ahead twice, only to knock-on, to his obvious frustration, over the line.
England aren’t short of quality hookers. Smith had a good game and scored his second try, from close-range, with five minutes left to bring up the half-century.
Pryce had gone off, so Lewis added the extras.
Having had a rest, Gannon and Holroyd returned in the final minutes and were involved in the set which led to Connor Wrench’s closing try.
Though the opposition was limited, it was a good, ruthless performance by England who have some real quality coming through below their senior side.
Last night was not an official international, but Jamaica are back in action a week on Sunday in a recognised Test against Scotland at Featherstone Rovers.
Jamaica: Woodburn-Hall, B Jones-Bishop, J Brown, Ogden, Johnson, Turner, Coleman, Peltier, Golding, Lawrence, Bravo, J Farrell, Tomlinson. Subs Magrin, Andrade, Williams, Agoro, McDonald, A Brown, Ball.
England Knights: Ashton, Halsall, Wrench, Broadbent, Marshall, Pryce, Lewis, Lawler, Walker, English, Pearce-Paul, Longstaff, McDonnell. Subs Smith. Gannon, Holroyd, Lees.
Referee: James Child (Dewsbury).
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