The match was played at high tempo and with a level of physicality that you would expect of a match of this importance between the two highest ranked teams in the world.
USA had the better of the opening half as the Germans pressed hard when not in possession, while the Stars and Stripe looked typically steadfast in defence. Meanwhile at the other end of the pitch striker Alex Morgan had the best sights of goal.
She firstly was denied by Nadine Angerer in a one-on-one opportunity after making a perfectly timed run behind the backline. Morgan then struck another effort wide from an acute angle from close range.
After the break Germany had a rare sight of goal as Anja Mittag pushed a header just wide, before drama on the hour mark. USA central defender Julie Johnston failed to deal with a bouncing through ball and fouled Alexandra Popp as the midfielder slipped in on the blindside.
However, Canada 2015 top-scorer Sasic pushed her spot-kick wide amid US celebrations and tears of relief from Johnston.
Nine minutes later it was USA’s turn to earn a penalty as Morgan’s charging run ended with a foul by Annike Krahn and the ever-reliable Lloyd tucked away the opportunity.
Germany pushed for an equaliser but USA sealed the contest with six minutes remaining as Lloyd dribbled into the penalty area and coolly pulled the ball back for O’Hara to gleefully fire home from close range.
USA will now face the winner of Wednesday’s second semi-final between Japan and England for the right to be crowned 2015 Women’s World Cup champions on Sunday in Vancouver.