Moscowinfo-iconRussiainfo-icon kicked off their Worldinfo-icon Cup in style on Thursday, thumping Saudi Arabiainfo-icon 5-0 in front of an ecstatic crowd in Moscow as President Vladimir Putin basked in the glow.

Putin declared the tournament open at the 80,000-capacity Luzhniki Stadium, saying footballinfo-icon "unites the entire world" before watching his team overwhelm their hapless Group A opponents.

In a performance beyond the wildest dreams of even the most ardent home fans, two goals from substitute Denis Cheryshev were the highlight as Russia ended a seven-match run without a win in style.

Iury Gazinsky got the party started early, heading Russia in front in the 12th minute before Cheryshev rifled home a second shortly before half-time.

Another substitute, Artem Dzyuba, made it 3-0 with about 20 minutes remaining before a delicious late goal from Cheryshev with the outside of his left boot and a fifth from Aleksandr Golovin sealed the rout.

Victory for Russia, ranked a lowly 70th in the world -- three places below Saudi Arabia -- was vital for the home nation's hopes of progressing, with tougher games against Egyptinfo-icon and Uruguay to come.

"There are no words to express what I'm feeling right now. I'm happy we won and happy I could help my team," said man-of-the match Cheryshev.

"I felt very happy when I knew I would be here in the squad but I never dreamed of anything like this."

Williams gesture

Earlier, British pop star Robbie Williams caused a stir during his performance at the opening ceremony by making an obscene gesture to a camera.

The former Take That star raised his middle finger at the end of his performance at the Luzhniki after appearing to mouth the words "I did this for free".

Russia is spending more than $13 billion (11 billion euros) on hosting football's showpiece, the most important event in the country since the 1980 Moscow Summer Olympics.

The buildup to the tournament has been dogged by controversy and diplomatic scandals and has shone a light on the challenges facing the country.

On the day of the curtainraiser, Russia freed the main opposition figure to Putin, Alexei Navalny, from jail after he served a 30-day sentence for organising an illegal protest.

But British gay rights activist Peter Tatchell was arrested for holding a one-man protest against the country's record on gay rights, hours before kick-off.

Big guns

The World Cup favourites -- Germanyinfo-icon, Spaininfo-icon, Franceinfo-icon, Brazilinfo-icon -- enter the fray from Friday onwards.

Brazil and star striker Neymar are seeking a sixth global crown while Germany, who won their fourth World Cup in Brazil four years ago, are determined to draw level with the South Americans.

France boast possibly the most talented squad while Lionel Messi is desperate to make amends for Argentinainfo-icon's defeat in the 2014 final.

The preparations of 2010 winners Spain were thrown into disarray after coach Julen Lopetegui was sacked just two days before their opening game on Friday against Portugalinfo-icon. He had angered his federation by accepting the job of Real Madrid manager.

Sergio Ramos and new coach Fernando Hierro displayed a united front on Thursday, smiling for the cameras as Spain scrambled to get their campaign back on track.

Almost 5,000 kilometres (3,100 miles) away, Lopetegui was being unveiled as the new Madrid coach, describing the day he was sacked as "the saddest day of my life since the death of my mother".

Neymar, the world's most expensive player, has recovered from a broken bone in his foot in time for the tournament.

Egypt's coach said prolific striker Mohamed Salah is "almost 100 percent" to play in their opening match against Uruguay on Friday after he had intensive treatment on the shoulder injury he suffered playing for Liverpool against Real Madrid in the Champions League final.

Hearts and minds

The money lavished on the tournament will boost Putin's already sky-high prestige at home by giving many of the 11 host cities their first facelifts in generations.

The tournament also offers Putin a chance to project Russia as a global player that is accepted and respected even while being at odds with the United Statesinfo-icon.

He is attempting to do so despite Russia being hit by international sanctions following its invasion of Ukraineinfo-icon's Crimea in 2014.

Moscow's military backing of the Syrian regime and alleged meddling in the 2016 USinfo-icon election on President Donald Trumpinfo-icon's behalf only deepened its worst rift with the West since the Cold Warinfo-icon.

Putin hopes the most-watched event on the planet provides Russia with the "soft power" needed to capture a sceptical world's hearts and minds.