As the peloton rolled onto the first climb of the day midway through the stage to Castro de Herville, INEOS Grenadiers launched the first of a series of blistering attacks with Pavel Sivakov and Tom Pidcock, splitting the GC group in the process.
Haig and teammate Gino Mader were able to follow while Miguel Angel Lopez (Movistar), third coming into the stage didn't have the legs and was left off the back, later sensationally abandoning the race and his podium spot.
Fellow Bahrain rider Mark Padun then dropped back from the early breakaway to join Mader and begin to work at the front of the group of favourites as they made their way up the final ascent of the day to the finish.
Pacing on the front, it took a team effort to close down a fiery late attack by Adam Yates (INEOS Grenadiers) and deliver Haig to the line with no significant time losses and complete a stellar all-around display by the team as Clement Champoussin (AG2R Citroen) won the stage.
Talking through how the day went down, Haig said the INEOS moves ensured massive gaps on tired contenders Lopez and Egan Bernal as long as himself and Mader could follow, which they did due to great positioning in the group.
“On the longest climb of the day there was a rolling plateau where people started to gamble and it just happened to be that Gino and me were in the perfect position,” Haig recounted.
“I knew if we were going to get away we needed one of the two Movistar riders, which would ideally be Enric [Mas] and one of the Ineos riders” - either Egan Bernal or Yates - [as] “it basically meant the group behind didn’t do any chasing.”
Haig praised Mader and Padun following the stage as he admitted third place is by no means locked up with tonight's tricky time trial still to come.
“They both did an awesome ride to the foot of the final climb. I knew Yates was going to attack on the steeper gradients to get as much of an advantage for the final TT, but I managed to limit my losses.
“It’s a nice position to be in, but it’s definitely not safe and done."
SBS' Matt Keenan echoed Haig's comments, identifying Bahrain as the clear winners of the day thanks to the trio of Haig, Padun and Mader.
"Stage 20, and the race continues to deliver in the most unpredictable of ways," Keenan said in his stage wrap.
"In the race for the general classification, hats off to Bahrain Victorious. In particular, Gino Mader and then Mark Padun sacrificed his own chances in the breakaway to drop back and support Jack Haig.
"Haig is in third place, with a 1 minute advantage over Adam Yates. Can he hold on to the podium?"
La Vuelta concludes overnight with Stage 21, a 33.8 kilometre individual time trial from Padrón to Santiago de Compostela set to decide the overall podium. Watch the action live from 1:50am (AEST) Monday morning on SBS VICELAND, SBS On Demand and the SBS SKODA Tour Tracker.
