Real Salt Lake is the first team from Major League Soccer to reach the semifinals of the tournament for professional teams in North America, Central America and the Caribbean.
RSL coach Jason Kreis was worried the team's stated goal to win the league would put it under too much pressure.
"We really raised the level of expectation for ourselves," Kreis said. "On prior occasions, we've seen we've struggled with that, so I was nervous again that the guys would come out very nervous tonight."
Real won the two-game total-goals quarterfinal easily after a scoreless draw at Columbus in the first leg. Real will face Deportivo Saprissa of Costa Rica or CD Olimpia of Honduras for a chance at the final.
Morales' first goal came in the 36th minute, making it 2-0 after Alvaro Saborio struck in the 23rd.
After the half, Columbus made it 2-1 on Andres Mendoza's goal from just outside the six-yard box.
Real missed chances on headers by Fabian Espindola in the 63rd minute and Saborio in the 68th.
Finally, in the 78th, Paulo Araujo Jr. fed Morales to put the game all but out of reach, though Columbus would have advanced if the game finished tied.
"You just keep the pressure on," RSL midfielder Will Johnson said. "You keep knocking on the door and eventually you'll hit one in."
Midfielder Andy Williams tacked on a fourth when he took a 20-yard free kick from an angle, hooked it over the four-man defensive wall and buried the ball in the left corner of the net in the final minute.
"Columbus came out in the second half and did what it had to do to get that first goal," Williams said. "It kind of made it interesting. It's a credit to everybody on our team that we took a deep breath and settled down and went back to work after that."