The Sky rider managed to shut down an attack by Alberto Contador (Tinkoff-Saxo) to place fifth on the first summit finish of the Italian Grand Tour.
Porte now trails race leader Contador by 20 seconds, with Astana's Fabio Aru only two seconds off the Maglia Rosa.
It was a confidence boost for the Tasmania with two weeks of the race still remaining.
“I think after yesterday there were a lot of tired guys and it’s obviously nice to be in that group (of favourites),” Porte told Cyclingnews.
“Hopefully I’m just going to be able to keep going like this day by day.
"I’m happy where I’m at, feeling good and looking forward to keeping on fighting."