International Champions Trophy: Inter Milan 1-0 Lyon
Inter had failed to win any of its past four pre-season friendlies but collected three ICC points on a poor pitch in Lecce to move off the bottom of the competition's table.
Luciano Spalletti's side struggled throughout the first half of Sunday's (AEST) clash and Samir Handanovic made three good saves to allow his team to go into the interval level.
However, seven minutes after the restart an improved Inter took the lead, Martinez providing a sweet first-time finish after an excellent Dalbert raid down the left flank.
Lyon, which had Memphis Depay, Bertrand Traore and Houssem Aouar on the bench, rarely showed any of its first-half pep and verve after the interval, with Handanovic mostly untroubled as he collected a well-earned clean sheet.
The Ligue 1 team will wrap up its ICC campaign against Chelsea, while Inter's last fixture in the competition comes against UEFA Europa League winner Atletico Madrid next weekend.