Updated

South Korea wasted a number of scoring chances against Mexico as they opened the Group B soccer competition at the Olympics with a 0-0 draw Thursday.

With forward Giovani Dos Santos starting on the bench, Mexico showed little promise of being a medal contender as its opponent dominated at St. James Park.

Both teams struggled to find their rhythm on the slippery turf with the second half tempo yielding more scoring occasions.

Koo Jacheol came close to breaking the deadlock in the 53rd minute as the South Korea captain swiveled to volley off the crossbar. Koo headed the game's best chance wide in the 80th after getting free inside the box.

Mexico next plays Gabon on Sunday, while South Korea will face Switzerland.