SHANGHAI -- Kemba Walker and Jayson Tatum are probably going to win a lot of games with the Boston Celtics over the next few years. Sunday they combined to play important roles in their first consequential win together as Team USA opened the FIBA World Cup with a 88-67 victory over the Czech Republic.

Tatum and Walker combined for 20 points in the first half as the U.S. got some separation after a bit of a sluggish start. The Americans played only five exhibition games -- some of their competition in the tournament played more than 10 -- and had revolving lineups and personnel, which made the start of pool play a bit of a soft open for this roster.

But Tatum has shot the ball well since the group got together for training camp a month ago in Las Vegas, and he drilled two 3-pointers out of the gate to keep that going. Tatum finished with 10 points.

Meanwhile the Czechs' game plan was to attack the smaller Walker with their best player, Tomas Satoransky, who has roughly 6 inches on him. Time after time, Satoransky went to the post to try to push around Walker.

The Chicago Bulls gave Satoransky a three-year, $30 million deal over the summer, in part, because of his ball skills for his size. But then the Celtics gave Walker $140 million because he's a star who is used to playing against size.

Walker (13 points) held his own, poking the ball away several times and not being afraid to foul when he lost leverage. At the other end, his quickness busted the overmatched Czech perimeter repeatedly. His stop-and-go actions and quick side-to-side moves drew "ohs" and "ahs" from the capacity crowd at the Oriental Sports Center.

Walker's performance was part of a strong U.S. defensive effort, which coach Gregg Popovich is hoping will be the bedrock of this team's run toward a third consecutive World Cup title. The Czechs shot only 35% in the first half as the Americans blocked five shots and pressured them out of their offense.

Popovich wants energy from his defense and he kept players fresh, playing 10 of them in the first quarter alone.

In the second half, Donovan Mitchell (16 points) and Harrison Barnes (14 points) provided much of the offensive punch as Team USA expanded the lead and was able to get its first win without much stress.

Star of the game: Walker ended up 6-of-8 from the field for 13 points along with four assists and a steal.

Stat of the game: After going just 2-of-14 from 3-point range in their last exhibition game against Canada, the Americans went 10-of-26 for a much better showing.

Up next: The Americans play their second of three pool games against Turkey on Tuesday (ESPN+, 8:30 a.m. ET). This is a rematch of the 2010 World Championship Game, and the Turkish team is likely the toughest competition in this pool for Team USA. It has three current NBA players: Cedi Osman, Ersan Ilyasova and Furkan Korkmaz, plus former NBA player Semih Erden. Ilyasova had 19 points and made five 3-pointers in Turkey's 19-point win over Japan on Sunday night.