Updated

The chant from fans sitting behind the Ghana bench filled the vast, mostly empty stadium early in the second half of Monday's friendly against South Korea.

"We want USA!" they hollered.

The Ghanians were feeling festive as their team won its last warmup match for next week's World Cup opener against the Americans by beating South Korea 4-0.

Jordan Ayew scored three times after entering the game as an injury replacement, and Asamoah Gyan also scored.

"It was a good friendly match," coach James Appiah said. "It was important we put out a good team. Everyone who paid to come in here got his money's worth."

Even so, Appiah said Ghana's not quite ready for its game against the United States next Monday in Natal, Brazil.

"It's fine we won, but we still have some work to do," Appiah said.

The Black Stars know what it takes to beat the Americans — they eliminated the U.S. team from the World Cup in 2006 and 2010.

The last friendly for Ghana and South Korea before the World Cup drew a small but enthusiastic crowd of less than 5,000, creating an atmosphere akin to a high school football game in the Miami Dolphins' 75,000-seat stadium.

Among those who had planned to be on hand scouting for the U.S. team were coach Jurgen Klinsmann, special adviser Berti Vogts and scout Matthias Hamann.

Ghana forward Abdul Majeed Waris left the game in the fourth minute with a left leg injury and was replaced by Ayew, who scored in the 13th minute when his shot from 15 yards deflected off defender Ki Sung-Yueng and past goalkeeper Jung Sung-Ryong.

Ayew nestled a kick into the corner of the net from 23 yards in the 53rd minute, and scored from close range in the 89th minute with an assist from Albert Adomah.

Asamoah Gyan, who scored the goal that clinched Ghana's win over the Americans four years ago, showed he's ready for the rematch. He stole the ball from Kwak Taehwi near midfield, dribbled 20 yards past Kim Younggwon and scored from 15 yards in the 44th minute.

Gyan and his teammates then celebrated with the azonto, a dance from Ghana popular in clubs there. The show of offense was a big improvement for Ghana, which lost its previous two friendlies 1-0 to Montenegro and the Netherlands.

"You learn from your mistakes," Appiah said. "Korea attacked really well. Playing against players with good pace, you have to be cautious in the back. We made good use of the counterattack chances we got."

The crowds will be bigger in Brazil. South Korea's first game will be against Russia at Cuiaba on June 17.

Ghana's speedy but disciplined defense limited South Korea to a handful of scoring chances. Lee Chung-Yong shot barely wide of the goal from 15 yards in the 15th minute, and Kim Bo-Kyung pulled a shot wide from 12 yards in the 67th minute. Ghana goalkeeper Fatau Dauda knocked away a shot by Son Heung-Min in the 40th minute.

Andre Ayew of Ghana whiffed on a scissors kick from close range in the 38th minute.

Jordan Ayew and teammate Mohammed Rabiu shook off a head-to-head collision midway through the first half.