Leeds came storming out of the blocks and thought they had got on the board when Walker crossed, only for referee James Child to rule it out due to obstruction in the build-up.
The Rhinos kept up their pressure and were rewarded thanks to a lengthy run from full-back Walker, which led to Sutcliffe crashing over as London struggled with Leeds’ impressive early tempo.
London ended the first half better than they started as they capitalised on a number of midfield mistakes from the Rhinos to break upfield before Morgan crossed over for their first points of the game.
After Myler was allowed to run clear from a Sutcliffe pass to score Leeds’ fifth try, London valiantly fought back in style after Abdull touched down once more and Walker pulled the Broncos within touching distance.
Leeds Rhinos interim coach Richard Agar:
“The two points were an absolute must today.
“Kallum Watkins got the boys to one side last night to talk about the magnitude of the game aside from the coaching staff, which shows great leadership from him in what is a trying time for us.
“We hung on and we composed ourselves for that last four or five minutes.
“It was being billed as a relegation battle but there’s still plenty of time to go.
“We’re not thinking we’re alright now because we’ve got two points here because from our performance it shows that there’s no real quick fixes for this. We’ve got to still keep working hard.”
London Broncos head coach Danny Ward:
“It’s another tough one but I don’t think we deserved to win. I thought Leeds were the best side over the 80 minutes.
“A couple of lads didn’t perform to their best and we can’t afford that, we need all 17 on the money.
“We didn’t execute as well as we should in the first half and, when we did in the second half, we caused them some trouble but we gave ourselves too much to do.
“We’ve got to handle that pressure from the off. Maybe the occasion got the better of them, maybe a couple were overawed but they’ll be better for the experience.”
Leeds: Walker; Briscoe, Newman, Watkins, Handley; L Sutcliffe, Myler; Seumanufagai, Dwyer, Singleton, Donaldson, Smith, Merrin.
Replacements: Parcell, Peteru, Oledzki, A Sutcliffe.
London Broncos: Walker; Dixon, Morgan, Kear, Williams; Abdull, Smith; Battye, Cunningham, Butler, Pitts, Lovell, Yates.
Replacements: Richards, Fozard, Adebiyi, Gee.
Referee: James Child