Newcastle: South Korea wasted a number of scoring chances against Mexico as the two teams opened Group B at the Olympics with a 0-0 draw on 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 Jacheol 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.
Mexico next plays Gabon on Sunday, when South Korea faces Switzerland.