Boxing: John Joe Nevin has guaranteed the first Irish medal of the 2012 London Olympics after an energy-sapping 19-13 win over Mexico’s Oscar Valdez in his bantamweight quarter-final this evening.

Nevin needed to box clever and he dealt with his fiery opponent with a mixture of footwork and well-selected shots.

He got caught with a powerful body shot in the last round and took his count but the damage was done on the scoreboard by then, against a highly-rated opponent who debuted at the Olympic Games in Beijing as a 17 year old and won bronze at the 2009 World Championships.

Valdez was a handful from the off and Nevin's brilliant footwork got him out of danger as the Mexican tried to pin him on the ropes. The Irishman settled into the round and landed some good shots but there was nothing between them by the first bell, with the scores at five apiece.

The second round was more controlled from Nevin and he enjoyed some success with his right-hook and uppercut to take the round 7-4 and move into a three-point lead.

The third was tiring for both fighters and before Nevin was dropped to his knee by the body blow, the Mexican looked weary having fruitlessly chased the elusive Irishman.

Next up for Nevin, is a semi-final bout for at least silver with Cuban number one and world champion Lazaro Alvarez Estrada on Friday.