The United States is on the brink of securing the top spot in Group K following Saturday's 69-53 victory over Greece at the 2019 FIBA Basketball World Cup.

There were fireworks on the court after the game, with ESPN's Brian Windhorst noting players from both teams had to be separated when the U.S. took exception to a hard foul Thanasis Antetokounmpo committed on Harrison Barnes.

Since Tuesday's close call against Turkey, Team USA has performed much better. The defense, in particular, has been excellent in wins over Japan and Greece with a combined 98 points allowed.

U.S. head coach Gregg Popovich and his staff still have some things to clean up before the knockout phase begins Tuesday. Kemba Walker (15 points) and Donovan Mitchell (10 points) were the only players to reach double figures in scoring, and the team shot just 36.4 percent.

Speaking to Windhorst prior to the game, Popovich noted the difficulties of trying to prepare for different teams that have unique and diverse ways of playing.

"In the NBA, you know each night the O's and X's and what people are going to run and that sort of thing," Popovich said. "But here every team has a different take on the way they want to play. It's actually enjoyable and challenging, as each team is a different artwork to be figured out."

Even though the United States hasn't always run like a well-oiled machine, the team is winning games.

Giannis Antetokounmpo did everything he could to help the Greek squad get a win. The reigning NBA MVP scored 15 points on 7-of-11 shooting and grabbed 13 rebounds. He received virtually no support from his teammates, however, who went 14-of-55 from the field.

Greece head coach Thanasis Skourtopoulos' strategy throughout this tournament has been unusual, especially when it comes to his best player.

Antetokounmpo has seemingly been lost in the rotation at times. His 11 attempts against the Americans were his most in this World Cup, but they all came in the first three quarters.

In Brazil's 79-78 comeback win over Greece on Tuesday, Antetokounmpo took only seven shots overall and played just 13 minutes in the first half.

Kostas Sloukas (13 points) led Greece with 12 field-goal attempts, and he made three of his six shots from three-point range. Leading scorer Georgios Printezis was held to six points on 2-of-10 shooting, and third-leading scorer Nick Calathes scored five points on 2-of-6 shooting.

Saturday's loss dropped Greece (2-2, six points) to last place in Group K heading into Monday's matchup against the Czech Republic (3-1, seven points).

The United States (4-0, eight points) is the only undefeated team in Group K and will secure a spot in the knockout phase with one more win.

Walker, Mitchell and Team USA will close group play against Brazil (3-1, seven points) at 8:30 a.m. ET Monday.