The BMC rider let rip 1.5 kilometres from the finish in pursuit of the leftover breakaway riders including Kastusha Alpecin's Haas and stage winner Andersen.
The Tasmanian now holds a 32 second lead over Sunweb duo Wilco Kelderman and Sam Oomen. More importantly, he enjoys a comfortable advantage over likely 2018 Tour de France Movistar rivals Nairo Quintana (45 seconds) and Mikel Landa (59 seconds).
"I think that after the amount of work that the team did for me today, I had to do something," Porte said. "I didn't really expect to take time like that. I wasn't feeling great yesterday but today I had a better day and the team was incredible for me. Each and every one of the guys was really good especially Michi Schär. He rode most of the stage for me. It's good coming into the Tour."
"The guys put me in a great position and they looked after me so I am happy with how the day went. This is a dress rehearsal for the Tour de France and it really showed today that we are there. It was good to take a little bit more time on some strong time trialists today. Tomorrow on paper is maybe better for me and I am super motivated."
"Allan Peiper said on the radio 'Richie if you have any gas, you gotta go,' and I actually thought I had hit out a bit too early but when I heard that they were cracking, I dug in a little bit more. It really hurt but it is nice to take some extra time."
Haas was disappointed but still upbeat after finishing second.
“That was an awesome stage!” he said. “Tour de Suisse is so nice when it’s not raining! I admit I’m a little disappointed to get second today instead of winning. Sunweb played the race tactic perfectly with Michael Matthews in the back, but it always hurts a little more to get beaten by the tactic where a guy sits for the last 30 k and we were pushing as hard as we could to actually win the race. Hats off – he’s an awesome rider and this is a big win for him, but what can I say? I put a lot of spirit into today.”
With two hors categorie climbs appearing in the first parts of the 186 kilometre stage, a breakaway was always going to form early and 18 riders did just that not long after the start in Fiesch. They held a five minute lead after the Klausenpass but Porte's charges took further control of the race to deliver their leader within two minutes of the remainder of the breakaway at the bottom of the final climb.
The 170 kilometre seventh stage finishes with a hors categorie climb in Arosa.
In this week's Zwift SBS Cycling podcast cycling journalists Jamie Finch-Penninger, Anthony Tan and Rob Arnold of RIDE Media join in the podcast studio for a passionate discussion about the key lead-up races for the Tour de France, as well as the local cycling scene.