Remco Evenepoel (Soudal-QuickStep) provided the biggest GC fireworks on the Vuelta a España's first summit finish on Monday, but Sepp Kuss (Jumbo-Visma) took away the unofficial prize as top climbing domestique of the day.
Here, there and seemingly everywhere on the two category 1 climbs in Andorra, Kuss first chased down an attack by UAE Team Emirates rival Juan Ayuso and then made a dig himself to try and test the GC rivals' strength.
As if that was not enough, Kuss then led out the main group of contenders close to the summit of the Arinsal, sparking one last split and giving his team leaders Primož Roglič and Jonas Vingegaard a chance to go for the sprint.
Vingegaard could not match Evenepoel's devastating final acceleration and had to settle for second, with Roglič placing fourth. Kuss himself lost a little time, suggesting rumours that he may be Jumbo-Visma's 'third man' for the GC, partly sparked by Roglič himself, may well be largely unfounded.
However, his show of climbing strength has confirmed that even if he is tackling this third Grand Tour this season, the American is more than up to the challenge.
"There was a lot of headwind in the final climb, that's why I thought it would be good for Primož," Kuss commented afterwards to reporters.
"But then when Ayuso attacked I went for it myself to make the leaders react."
"I had Jonas and Primož close by behind me. Then when I saw a gap was not possible on the climb, I tried to keep things together for them for a sprint at the summit."
A stage winner in Andorra in the Tour de France a few years back and fully familiar with both its mountain roads and meteorology from his own time there as a resident, Kuss agreed that the Vuelta - which managed to dodge some heavy rain showers on its ascent of the Arinsal - had been lucky with the weather. After two days of torrential downpours, the race was certainly due some good fortune.
"We were lucky today, there were some wet roads coming off Ordino but it was pretty safe," Kuss said. "When you get the good weather here, Andorra is amazing."
The Vuelta will quickly leave the Pyrenees but not without clarifying the relative strength of several GC favourites. For one thing, Kuss agreed that Ayuso, third last year at 19 and one of the most aggressive riders in Andorra on Monday, would be a major challenger for the overall battle.
"He's a big rival for the podium," Kuss recognised, "he already showed last year how much talent he has."
However, Andorra also showed, too, that Kuss will be a key factor in Jumbo's mountain game plan as well in this year's Vuelta - and that's a lesson their rivals won't forget, either.
