The United States could not have scripted a better start to their World Cup as a Folarin Balogun brace and Gio Reyna curler fired the co-hosts to a 4-1 drubbing of Paraguay in front of Hollywood royalty in Los Angeles on Friday.

The hosts took the lead in the tournament's first game on US soil within seven minutes thanks to an own goal, and by the end of an utterly dominant half the home fans were in dreamland, their side up by three.

Tom Cruise, Leonardo DiCaprio and Paris Hilton were among a sold-out 70,492 crowd as the US, co-hosting the tournament with Mexico and Canada, piled wave after wave of attacks on the South Americans, with Reyna polishing off the win late in stoppage time after Mauricio had pulled one back.

The win and emphatic scoreline puts the US in a favorable position already to progress from Group D, which also contains Australia and Turkey.

The game had been preceded by a Tinseltown-style opening ceremony. Katy Perry delivered the headline performance, accompanied by singers Future, Tyla, Anitta and K-pop star Lisa.

Earlier in the day, co-hosts Canada grabbed a second-half equalizer to draw 1-1 with Bosnia and Herzegovina in Toronto on Friday, earning their first-ever point at a World Cup.

Cyle Larin levelled for the home team in the 78th minute after Jovo Lukic put Bosnia ahead midway through the first half in the first World Cup finals game played on Canadian soil.

Canada threatened a winner in the closing moments but had to settle for a draw and will next face Asian Champions Qatar in Vancouver on June 18.

"It was special for me. I was ready to come and help the team," said Larin. "I thought the goals would come. I score when Canada needs me, and always have done.

"We just have to stay concentrated. We'll be playing at home and just have to push the limit."