|Betfred Super League|
|London Broncos (12) 23|
|Tries: Morgan 2, Cunningham, Pitts Goals: Dixon 3 Drop-goal: Smith|
|St Helens (12) 22|
|Tries: Roby, Thompson, Percival, Grace Goals: Richardson 3|
Super League's bottom side London Broncos recovered from an early 12-0 deficit to inflict a shock golden-point defeat on runaway leaders St Helens.
Morgan Smith's drop-goal proved the difference after a see-sawing contest, which Broncos looked set to win in 80 minutes before Regan Grace's late try.
London twice had to come from behind, trailing 12-0 inside 10 minutes and then 16-12 in the second half.
Saints are still four points clear despite only their second loss of 2019.
Few would have predicted this result at the Trailfinders Sports Ground, with Justin Holbrook's side having won 15 of their previous 16 Super League matches - one of those a 26-0 thrashing of Broncos in the reverse fixture.
The Challenge Cup semi-finalists looked set for another comfortable afternoon when captain James Roby and Luke Thompson both crossed inside a dominant opening 10 minutes.
But Ryan Morgan, on loan from Saints, and James Cunningham levelled before half-time as the battling Broncos fought to avoid a 13th loss of the season.
Mark Percival got Saints back on track after the break, crossing to make it 16-16, only for Morgan's second try to again wipe out his parent club's advantage.
Jay Pitts put London in front for the first time in the game with 12 minutes left and the Broncos skipper looked destined to be the match-winner until Grace's 79th-minute score.
But the hosts were not to be denied and Smith's drop-goal in added time completed a memorable victory.
After the match, Holbrook confirmed that Roby will have groin surgery this week and is likely to miss Saints' next four games.
London Broncos head coach Danny Ward told BBC Radio London:
"It's hard to find many negatives, the boys were fantastic from 1-17. They really just worked their socks off, defended like their lives depended on it, put the one-percenters in and we felt the buzz that they were going to win.
"They went 12-0 down but got back into the game by knocking off sets and building pressure.
"We worked on golden point during the week, put them in scenarios in training and it wasn't the greatest, but that's why you train. It couldn't have worked out any better."
St Helens head coach Justin Holbrook:
"I was disappointed not to win, but it was a great game of rugby league at the end of the day. Well done to London to come away with the win.
"We just made a couple of errors, a few too many errors, we lost the ball and they picked it up. They were the better side in the second-half.
"Credit to them, we know how hard a team they are, they showed it at the end of the day."
London Broncos: Walker; Dixon, Morgan, Kear, Williams; Abdull, Smith; Battye, Cunningham, Krasniqi, Pitts, Gee, Yates.
Interchanges: Butler, Richards, Ioane, Fozard.
St Helens: Welsby; Swift, Naiqama, Percival, Grace; Lees, Roby, Thompson, Peyroux, Paulo, Knowles
Interchanges: McCarthy-Scarsbrook, Amor, Ashworth, Costello