Halifax were left facing a make-or-break Championship showdown with Toulouse at the Shay next Sunday after they fell just short of a famous win in London.
Richard Marshall’s side dropped out of the top four after a 20-18 loss against the Broncos, but know that a win over the French side and a final day victory over Rochdale would almost certainly be enough to secure a place in the Super 8s Qualifiers.
The visitors had looked to be slipping out of the contest against their full-time hosts when winger Rhys Williams scored his second try of the game to open up a 14-0 lead with a little over half an hour to play.
But Australian full back Kieren Moss touched down after Will Sharp’s break sparked the visitors’ attack, Steve Tyrer narrowing the gap to 14-6.
And with Fax ratcheting up the pressure, London’s lead shrank to 14-12 when Shane Grady scored from Ben Johnston’s pass and Tyrer added the extras.
An error from the kick off gave the Broncos some much-needed possession though and Ben Evans scored by the posts, Kieran Dixon converting for what looked like a decisive 20-12 lead inside the final 10 minutes.
Fax weren’t done though, Jacob Fairbank crossing the line for Tyrer to again cut the gap to two points inside the final two minutes, but time ran out as they pressed for an unlikely win.
The Broncos, who had faced their chances of a Super 8s Qualifiers place being left in tatters by a defeat, had applied the early pressure, dominating field position and taking a 13th-minute lead when Williams danced over by the corner flag.
Dixon’s conversion attempt drifted wide, and Fax had a chance of their own soon after, Fairbank breaking clear and their own Londoner, James Woodburn-Hall, being stopped short of the line.
Skipper Scott Murrell was also held up on the line just past quarter time, but it was London who added to their lead after 25 minutes, Williams fielding a kick and putting full back Alex Walker over, Dixon finding the target for a 10-0 lead.
The visitors enjoyed more possession as the half drew to a close, and while they were unable to find a way through before the break, the stage was set for a second half revival.
London: Walker; Dixon, Hellewell, Kear, Williams; Pewhairangi, Cunningham; Battye, Peliessier, Evans, Pitts, Hindmarsh, Davis. Subs: Spencer, Ioane, Harrison, Sammut
Halifax: Moss; Saltonstall, Tyrer, Woodburn-Hall, Sharp; Murrell, Johnston; Tangata, Kaye, Fairbank, Butler, Grady, Grix. Subs: Maher, Moore, Morris, Barber
Referee: James Child