Russia quickly dispelled months of pre-tournament angst in Moscow on Thursday, dominating Saudi Arabia to claim a 5-0 win in the 2018 FIFA World Cup opener.

Stanislav Cherchesov's team took just 12 minutes to lift the cloud of negativity, an Iury Gazinsky header putting the team 1-0 up, before substitute and eventual man of the match Denis Cheryshev extended the lead just before halftime.

The traffic was again one-way in the second half, substitute Artem Dzyuba scoring the game's third in the 71st, just one minute after coming on.

Cheryshev and Aleksandr Golovin then ended the game with an injury-time flourish, the former curling the ball past the keeper with the outside of his left foot for the game's fourth and the latter making it five by putting a free kick over the wall and inside the right upright.

"I am extremely pleased that this is the situation and we won, but we shouldn't stop here," two-goal hero Cheryshev told a packed post-match press conference. "At any moment when you relax you can be kicked out, just as simple as that."

Saudi Arabia's Argentinean coach Juan Antonio Pizzi's hope that his team would play a stingy, tight brand of defensive soccer was quickly out the window as the home side cut his back four to shreds early and often.

And for all the talk of the Middle Eastern team's ability to play a skillful, controlled passing game, the frequency with which they surrendered possession made his squad often look amateurish.

Russian manager Cherchesov slapped down suggestions the big win was going to inflate the team's sense of worth, or as one journalist put it, to put "a crown on their heads."

"I don't think we are dealing with that danger here. We understand clearly why we are here."

"It is just the beginning, not the end. We won 5-0, we got three points, however, we could have played 1-1 and nothing would have changed. This is a tournament, and in this tournament we need to gather the points we need to leave the group."

Gazinsky allowed the 78,011-strong crowd to breathe a collective sigh of relief when he put the home team 1-0 up in the 12th minute.

Saudi Arabia were unable to deal with a Yury Zhirkov corner, and when the ball was floated to the back post by Roman Zobnin, FC Krasnodar's Gazinsky found himself in ample space for a free header which he put to the left of flailing goalkeeper Abdullah Almuaiouf.

After the goal, the Russians were able to sit back and wait for the Saudis to lose the ball, which they did all too often.

Whenever in possession the Russians looked dangerous, Gazinsky's club teammate Fedor Smolov and CSKA midfielder Golovin breaking with pace at every opportunity.

And after several close calls for the Saudis, Russia went two up just before halftime when Cheryshev showed excellent poise in allowing two desperate tacklers to slide by before smashing into the back of the net with his left boot.

Villareal's Cheryshev, who came onto the pitch in the 24th minute when Alan Dzagoev went down with an apparent hamstring injury, collected the ball from Zobnin and calmly lifted the ball over the defenders before blasting home.

"It was a very quick moment," said Cheryshev when told his goal was getting global attention.

"The pass was a little short and I had to play the way I did. I succeeded, the defenders took a slide, and I just tried to score, to hit the ball, and I am happy that I was successful."

With Saudi Arabia looking as impotent as ever in the second half, it seemed only a matter of time before Russia would score again, and Dzyuba answered the call.

The big Arsenal Tula striker met a Golovin cross inside the box, holding off another futile Saudi defensive effort to head home.

Adding insult to the Saudi's significant injuries, Cheryshev and Golovin's injury-time goals were of the finest quality.

Cheryshev looped the ball in with a beautiful strike and Golovin spun the ball over the wall to make it 5-0, Russia's biggest World Cup win since the Soviet Union put six past Hungary at the 1986 tournament in Mexico.