London were the better of the sides in the first half and a try by Morgan Smith either side of kicks by Kieran Dixon put the hosts in the ascendancy before Weller Hauraki’s converted try made the score 8-6.
The floodgates opened in the second 40 minutes and after the visitors scored further tries through Adam Quinlan and Chris Atkin, Broncos wrestled back control after a four-point score from Alex Walker and a further effort from Jordan Abdull.
Both teams continued to pile forward, but Rob Butler made the game safe late on before Josh Drinkwater bagged a late consolation.
Rovers now sit bottom on 12 points, level with Leeds, with London a win clear on 14.
Despite the tension surrounding the fixture, there was a lot of open, expansive rugby on display, with the lion’s share of it coming from the hosts.
It was Danny Ward’s charges who were first on the scoreboard, with London’s 2019 top scorer Dixon slotting his penalty just inside the right-hand upright after six minutes.
London got the first try after 26 minutes. Nathan Mason fed Dixon on the right wing and the former Hull KR man showed expert vision to kick through the gap. Morgan Smith latched on to the loose ball and charged through to roars from the crowd.
Dixon’s second penalty then made it 8-0 and it was beginning to look slightly ominous for Rovers, but they ended the half with a try of their own to give Tony Smith’s team talk a much more positive feel.
Drinkwater slid an inch-perfect kick through for Hauraki to halve the deficit, before Shaw’s conversion to make it 8-6.
Hull KR picked up where they left off immediately after the break and a stunning team move saw them surge into the lead.
Kane Linnett’s confident charge was then followed by a nifty pass to Quinlan, with the full-back receiving a return pass from new arrival Harvey Livett to scramble over under pressure.
Broncos could scarcely believe what happened next. After the hosts switched off at a penalty, Luis Johnson showed speed of thought to dart through the middle and found Atkin, who made no mistake before Shaw scored his second conversion.
Fifty-three minutes in, Ward’s men managed to close the deficit courtesy of a scintillating move involving Matty Fozard, Eddie Battye and Morgan Smith, before Alex Walker crossed.
The video referee was not used until midway through the second period and it was deemed that Dixon had not tackled Shaw without the ball and therefore Abdull’s grounding was good, sparking wild scenes.
Victory was secured through Butler, with the prop shrugging off the attention of several Rovers players to roll over, before Drinkwater’s late converted try put the fans on edge.
London Broncos: Walker, Dixon, Morgan, Kear, Williams, Abdull, Smith, Battye, Cunningham, Krasniqi, Pitts, Gee, Yates. Substitutes: Ioane, Fozard, Mason, Butler.
Hull K R: Quinlan, Shaw, Linnett, Crooks, Hall, Drinkwater, Atkin, Mulhern, Lawler, Masoe, Hauraki, Tomkins, Johnson. Substitutes: J. Keinhorst, Lee, Murray, Livett.
Referee: Chris Kendall (RFL).