Morgan scored the eventual winner in the 53rd minute as the second-ranked United States advanced through to the quarter-finals of the Women's World Cup on Monday with a 2-0 victory over 28th-ranked Colombia.
"We knew it was going to be a challenging game today," said American coach Jill Ellis. "I thought we were persistent and that our chances would come as we controlled most of the ball and limited their chances. I had faith that at some time that we would break through. I am obviously very pleased to be moving on."
The Americans briefly appeared to score in the fifth minute, as star striker Abby Wambach rushed to slip a rebound past Colombian goalie Catalina Perez, but was ruled to have been offside on the play. Perez was in for regular starter Sandra Sepulveda, who was suspended for a pair of group-round yellow cards.
Perez was then forced to make a big save on Wambach in the 14th minute.
The game remained 0-0 at the half.
Unbelievably, Perez was thrown out of the game early in the second with a red card after coming out of her net and taking the legs out from under Morgan, forcing Colombia to use third-string goalie Stefany Castano and play a member short.
The U.S. was awarded a penalty shot on the play, however Wambach shot the ball wide of the net.
The States made up for that just a few minutes later as a hard shot from Morgan went off of Castano's hand and into the Colombian net.
The American side got some insurance with yet another penalty shot in the 66th minute, this one a successful shot by Carli Lloyd.
"It's a huge match for us and a confidence booster," said Lloyd, the player of the match. "We improved a bit and found the net. We're creating some chances and I am confident more will come. It's good for our confidence moving forward to the next game."
It was the United States' 30th win in its history of World Cup play, having previously defeated Australia 3-1 and Nigeria 1-0 to go along with a scoreless draw with Sweden to win Group D.
The American squad won the silver medal at the 2011 World Cup in Germany and went on to win Olympic gold in London in 2012. The two-time World Cup champs have not claimed the title since last winning in 1999.
It was the second World Cup appearance for Colombia, which lost two of its three games in Germany in 2011. This time around the South American country upset France 2-0 in the group stage of the tournament, while tying Mexico 1-1 and losing 2-1 to England.
"Our players played with an iron will from the beginning to the end of this match," said Colombian coach Fabian Taborda. "I was very pleased with the performance of our team. At times the best team in the world didn't look that good as a result of the way we performed.
"Hopefully in four years we will be able to advance even further."
The U.S. women will now face 16th-ranked China in the quarter-finals on Friday in Ottawa. They will be without midfielders Lauren Holiday and Megan Rapinoe, who picked up their second yellow cards of the tournament against Colombia.