Herrada, whose older brother Jose also rides for Cofidis and who is racing the Vuelta, too, was the best placed rider on GC in an 18-man breakaway that gained more than 12 minutes on the main peloton at one point on stage 12's hilly trek across northern Galicia.
Sixteenth on the finishing line, Herrada's advantage allows the 28-year-old Spaniard to move into the lead by more than three minutes on Yates. And although Jesus Herrada is not considered a pre-race GC favourite, it may well prove no easy task to oust this talented all-rounder and former double road race national champion from the Vuelta's top spot overall.
Herrada, who left Movistar at the end of last season with his brother Jose in search of greater freedom of manouvre, said that his initial objective when getting into Thursday's big break was a stage win, not the lead.
"The overall was a kind of goal, but secondary to my going for the stage win," Herrada explained. "Now that I've got the lead, though, I will try and defend it for as long as possible, though I have no idea how long that will be.
"Since the beginning of the season, I've been going well, but I haven't managed to get an actual win. But I've kept progressing and I'm very pleased to be here."
Herrada is currently one of two leaders of a Vuelta classification for Cofidis, along with Luis Maté, the rider who has dominated the race's mountains classification since the Vuelta left Malaga on August 25.
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Asked how he now views his chances in the race more globally, or as one journalist rather poetically put it, when the Vuelta rolls into Madrid in two weeks time, Jesus Herrada responded rather tartly.
"You want to know how I imagine myself in Madrid? Finishing the race, I hope," he said.
When another reporter put it to him that he did not seem particularly overly emotional about the highest-profile success of his career, Herrada once again downplayed the spectacle around him.
"It's just that I feel a bit weird having to do all this stuff with the media and all the hullabaloo you get by being leader of the Vuelta," he said. He did, however, give his brother Jose a big hug when the two met up after the finish.
As a first time Grand Tour leader, Herrada may not yet be used to the media fuss, but some GC riders feel that the Spanish all-rounder may well have time for that, as Herrada could be more of the GC challenger in him than some teams have estimated. Indeed, in interviews earlier this year, Herrrada said one of his goals was to challenge for a GC result in a Grand Tour. Now he has had that opportunity thrust upon him.
Both Miguel Angel Lopez (Astana Pro Team) and former teammate Alejandro Valverde (Movistar) warned that Jesus Herrada could be tricky to dislodge from the top spot overall, despite the three summit finishes over the weekend that now await the Vuelta peloton.
"I think it will be hard to put time into him," Lopez told the Vuelta's official website, whilst Valverde added, "I don't think he'll lose the red jersey on [stage 13's ascent of the] Camperona."
Jesus Herrada's hold on the red jersey is special from a historical view, given its rarity. Born in the region of Cuenca, he is the second Spanish rider from that area ever to hold the lead, and the first in nearly half a century, more specifically since Luis Ocaña, born in the Cuenca village of Priego, won the Vuelta outright in 1970.
"That's a real honour for me," Herrada recognised.
