South Korea wasted a number of scoring chances against Mexico as the two teams opened Group B soccer at the Olympics with a 0-0 draw Thursday.
With forward Giovani Dos Santos on the bench from the start, 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, but the tempo picked up in the second half, which saw more scoring occasions.
Koo Ja-cheol came close to breaking the deadlock in the 53rd minute as the South Korea captain swiveled to send a volley off the crossbar. Koo headed the game's best chance wide in the 80th after getting free inside the box.
Substitute Raul Jimenez nearly helped Mexico escape with three points but curled his effort off the post after a swift counterattack in the last minute of play.
While South Korea was without creative midfielder Han Kook-young because of a broken left foot, it still continued to create better opportunities after the break before goalkeeper Jose Corona tipped away Ki Sung-yueng's rising shot.
Dos Santos replaced Oribe Peralta in the 66th and soon had an effort deflected wide. Dos Santos then met Darvin Chavez's ball into the area in the 88th but guided his shot wide of the post.
"We expected a game like this," Mexico coach Luis Fernando Tena said. "We never thought it would be easy. I think it was a fair result."
Mexico plays Gabon on Sunday, while South Korea faces Switzerland.