The Norwegian pairing have been ranked as the top men’s team for the past 47 weeks and have won seven of their past 10 International Volleyball Federation World Tour events.

It gave Cuba’s Sergio Gonzalez and Luis Reyes a nightmare opening match of the tournament, as pool matches started at Am Rothenbaum Stadium.

Mol and Sørum showed their class by easing to a straight sets victory in the Pool A clash.

The duo emerged comfortable 21-10, 21-14 winners.

Alexander Brouwer and Robert Meeuwsen, the 2013 world champions, secured a hard-fought victory in Pool F.

The Dutch duo, who won Olympic bronze at Rio 2016, beat Canada’s Ben Saxton and Grant O’Gorman 23-21, 19-21, 15-9.

The pool also contains Beijing 2008 Olympic gold medallist and 2007 world champion Phil Dalhausser.

Dalhausser and his team mate Nick Lucena earned an opening day win, the Americans beating Argentina’s Julian Azaard and Nicolas Capogrosso 21-14, 21-13.

Defending champion Laura Ludwig enjoyed a strong start in the women’s event with her new partner Maggie Kozuch.

The German duo won 21-19, 21-15 in front of their home crowd against the United States’ Kelley Larsen and Emily Stockman in Pool J.

The group stage of the competition will take place until July 3.

Quarter and semi-final matches will be staged on July 6, with the medal matches held the following day.