Kailer Yamamoto stepped up with two goals and two assists, and Clayton Keller had two goals and an assist.

Logan Brown potted a goal and an assist. William Lockwood, Kieffer Bellows, and Joey Anderson all scored one apiece. Defenceman Chad Krys had two helpers.

"Being the first game, there’s always emotion and you come out excited," said head coach Danton Cole. "I thought they did well."

Bottom line: it’s going to be tough for anyone to knock off the defending champions. Relying on the depth and talent of their National Team Development Program, the Americans have won six out of the last seven U18 tournaments. They're shooting for their third straight title here.

"It was a good game," said Yamamoto. "Russia definitely played their hearts out. I think we got a couple of flukey goals in the third period. It’s just good to get the win."

Yaroslav Alexeyev and Ivan Kozlov replied for Russia, which was outshot 45-22.

The Russians have sent an inexperienced and little-known roster to this tournament, consisting largely of U17 players. Only three players on the team are 1998-born.

Russia has won the U18 three times (2001, 2004, 2007), but looks like a long shot to repeat the feat this year.

"We’re a young team, obviously," said top 1998-born defenceman Mikhail Sergyachov. "We didn’t do a lot in the offensive zone, and in the defensive zone we didn’t play our structure. But we were trying. We’re trying to improve ourselves and show ourselves, do something."

Keller opened the scoring unassisted at 3:44, racing in and releasing a low shot that squeezed past the right pad of Russian starter Maxim Zhukov.

Just 44 seconds later, the U.S. jumped into a 2-0 lead. Trent Frederic dished a backhanded saucer pass to Sanchez, who scored high to the stick side.

Russia promptly cut the deficit to 2-1. At 5:17, after Dmitri Samurokov came in off the center point and fired a shot, Alexeyev converted the rebound from in tight.

Zhukov had to be sharp to foil Brown on a clear-cut break with just over seven minutes left in the first period.

Sanchez nearly gave the Americans a two-goal lead when he zinged one off the crossbar early in the middle frame. Russia came right back down the ice, and Kozlov made it 2-2 at 2:21 when he surprised U.S. goalie Jake Oettinger with a wrap-around goal.

The U.S continued to come on strong, with Keller testing Zhukov from different angles. Chants of “USA! USA!” rose from the stands.

Mistakes would prove to be Russia's undoing.

At 16:18, Keller made it 3-2, cutting down the right side and fooling Zhukov with a bad-angle backhander from the goal line.

"That guy, I don’t know how he does it, on the bench," Yamamoto said admiringly of Keller. "I’m still speechless from the game, from what he’s done out there."

It only took another 14 seconds for Bellows to stretch the gap to 4-2, as he busted in alone and slid it through the goalie’s pads.

In the third period, Yamamoto put the game out of reach, getting the 5-2 tally at 6:19 during a goal mouth scramble.

"I think he was getting a little bit tired in there and we took advantage of that," said Yamamoto of the Russian goalie. "It was good."

Defenceman Mikhail Kozlov was unable to move Anderson from the front of the net, and the American assistant captain lifted home a power play rebound to make it 6-2 at 7:30.

Yamamoto got the seventh U.S. goal with a man advantage marker, as Russian blueliner Alexander Alexeyev inadvertently tipped the puck past his own netminder. Zhukov was relieved by backup Danil Tarasov for the rest of the game.

"Kailer played a great game," said Cole. "He’s a warrior. He’s not the biggest guy out there, but he’s in front of the net and he’s scoring goals there and he’s making plays."

Brown rounded out the scoring with six minutes left.

Before the game, an opening ceremony with youngsters brandishing the flags of the 10 competing nations took place. Tournament chairman Frank Gonzalez declared the 2018 IIHF U18 World Championship open.