The Colombian's ascent of La Camperona on stage 13 was affected by a mechanical incident half-way up, apparently when his chain jammed, but on this occasion his ascent of Praeres could not have gone more smoothly.
López and compatriot Nairo Quintana (Movistar) shadowed each other closely on the climb, accelerating away from the tiny group of favourites on two occasions. But ultimately neither could shake off the other, indirectly favouring stage winner Simon Yates (Mitchelton-Scott), who bridged across to the duo with Rigoberto Urán (EF Education First-Drapac), and then went on for the win.
López – who finished third at this year's Giro d'Italia and took two stage wins at the 2017 Vuelta stage – played down the importance of the ascent in the bigger picture of things.
"An attack where you can only get 10 or 20 metres' advantage doesn't really matter much long-term," he said.
"On these ultra-steep climbs, one person goes at 11.5 kph and another at 12 kph, and the gaps are small. It's on the less-steep ascents where you can really get an advantage."
'Superman', as López is nicknamed, said that he preferred to concentrate on one of the two Movistar racers – "in my case, Nairo" – because, he argued, it was impossible to keep both Quintana and Valverde under control.
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López has moved up a spot on the GC from fifth to fourth, but his advance is purely to do with Cofidis rider Jesus Herrada's disappearance from the top placing overall. At the moment, he feels, there is everything to play for and nothing major has yet been decided.
"Nobody's got a real advantage yet," he said. "Everybody's very close together. It's on Lagos where you'll see the big, long-distance attacks going clear. Sunday's going to be really important."
Consequently, López does not believe that the race has yet come down to the top five or six on GC. There are still 10 riders within two minutes at the top of the classification and, he says, it will mean fighting hard until the last day.
"I've done the Giro, and the Vuelta before, and I know that this is a race where you have to fight to the last day.
"In that sense, Yates' weak point isn't his team. He's got a squad that will be able to defend his lead, if he keeps it, into the third week."
López's position is, in any case, an interesting one. Whilst much of the focus appears to be on Mitchelton-Scott and Movistar, the Astana racer is perfectly positioned to take advantage of the two teams' determination to mark each other's moves closely.
Just how much he can actually benefit from that situation, though, will only become clear on Sunday. As López puts it, there is still everything to play for in this year's Vuelta.
Alasdair Fotheringham has been reporting on cycling since 1991. He has covered every Tour de France since 1992 bar one, as well as numerous other bike races of all shapes and sizes, ranging from the Olympic Games in 2008 to the now sadly defunct Subida a Urkiola hill climb in Spain. As well as working for Cyclingnews, he has also written for The Independent, The Guardian, ProCycling, The Express and Reuters.
