Martins did well to turn and shoot a couple of minutes into the first half of extended play - but his strike went over the bar from just inside the penalty area.
First US international Clint Dempsey struck the bar with a 30-yard strike and then Murphy repeated the trick with a curling shot from just outside the area.
Gerrard came close to opening the scoring when he collected a Torres pass and curled a dipping first-time strike towards goal, only for a back-tracking Brad Friedel to tip it over the bar.