The Team Sky leader surged clear of the peloton just short of the summit of the 1km-long, category-three Cote du Salario, which arrived 13km from the finish.
He later sat up and rejoined the pack, but the ease with which he rode away from his general classification (GC) was an ominous warning for the rest of the race.
Froome said: "That little climb, about 10km from the finish, I knew the descent was tricky and dangerous.
"I was on the front with Richie [Porte] and I thought it might be a good time just to push on a little bit, get ahead and take the descent at my own pace and stay out of trouble. It is always good to keep people on their toes.
"The main objective for us was to stay out of trouble today, stay at the front, and not lose any time to the main contenders.
"All in all, it was a good stage for us having kept our places on the GC [general classification]."
Stage two was won by Jan Bakelants, who also claimed the race leader's yellow jersey.
The RadioShack-Leopard rider formed part of a breakaway group 6km from the finish line alongside Juan Antonio Flecha, Sylvain Chavanel and three others.
He later surged clear on his own in the final kilometre and hung on to secure the first professional win of his his career.
"I am incredibly happy," the 27-year-old Belgian said. "I have never won a race in the professional ranks.
"When Flecha went, I said 'I go' because I know he always gives the maximum. Chava was there as well - always a guy who wants to ride.
"We were a six and we cooperated pretty well, but I knew in the end we would start looking at each other and maybe we wouldn't keep it [the lead].
"I said, 'You give everything now you have', and I started pushing my level. It maybe didn't look nice, but I went fast.
"I had a decent gap. I say, 'Just pedal, it doesn't matter if they come back'. No regrets after this."