Back in the same race for the first time since 2012, Porte took part in a three-up move also containing Luis Angel Mate (Cofidis), the Vuelta's current King of the Mountains, and Burgos-BH's Jorge Cubero.
The trio went on the attack after just a few kilometres, and although on a flat stage it was all but inevitable that the sprinters' team would finally reel them in, remained out front for nearly 125 kilometres after gaining a maximum of four minutes.
The stage 6 breakaway was a first big indication of Porte's steadily improving condition in the Vuelta, something he had commented in the morning to the press, and which later had him reflecting on when he last went on a similar attack in a break.
"It was maybe in the Vuelta 2012 when I got second at the Bola del Mundo behind [stage winner Denis] Menchov," Porte related as he rolled to a halt outside the BMC team-bus.
"It's been a long time since I was allowed to jump in a breakaway. Of course, it was never going to go all the way to the finish but it was nice to get something out of a stage like that. It was an enjoyable day out there."
With Cubero going for the intermediate sprint and Maté seeking to buttress his mountains classification lead, Porte described the breakaway as a "win-win for all of us."
"It wasn't really too hard, it was more [difficult] when it came back there, it got pretty hectic there in the crosswinds when the bunch caught there."
He had come through the late splits and crash unscathed, although as he commented wryly about the bollards which caused the accident, "you'd have thought they could have taken those out."