Reigning champions Canada defeated Norway 3-1, as the USA crushed Slovakia 7-1, hosts survived an early scare to see off Slovenia 5-2, and Finland overcame Austria 8-4
Shea Weber and Jamie Benn were the heroes for Canada - seeking to win their first Olympic gold outside North America since Oslo 1952 - as they each grabbed second period goals to down Norway, following a slow start.
A mistake from goaltender Carey Price let Norway back into the game in the third, before Drew Doughty restored Canada’s buffer minutes later.
Canada outshot Norway 38-20, but the Scandinavians showed that they are not in Sochi to make up the numbers.
Earlier in the day Russia also took their Sochi bow in front of more than 11,000 spectators at the Bolshoy Ice Dome. Star man Alex Ovechkin delighted the majority of them by scoring with his very first shot against Slovenia.
At 2-0 it looked comfortable, but the hosts had to endure a scare, as Olympic debutants Slovenia narrowed the gap to 3-2 thanks to a double from Ziga Jeglic and some superb shot-stopping from goaltender Robert Kristan (30 saves), before Russia finally made the win safe with two late goals.
“We tried to play too beautiful for our fans,” Ovechkin said. “It is good to get this kind of lesson," he said. "When you get a 2-0 lead you feel like the game is going to be easy and we stopped playing.”
Elsewhere the USA - beaten finalists at Vancouver 2010 - conjured six goals in the second period as they thumped Slovakia 7-1 at the Shyaba Arena, Paul Stastny netting twice.
In the morning match at the Bolshoy Ice Dome, Finland found themselves 3-1 down in a high-scoring first period against Austria, before levelling at 3-3.
The Finns overcame the early fright and eventually made their dominance count, running out 8-4 winners, despite an impressive hat-trick for Austria from Michael Grabner.