Cameron Burgess turned the ball into his own net after 11 minutes under pressure from Folarin Balogun, before Alex Freeman doubled the lead in first-half stoppage time, heading home a rebound after his initial effort was blocked.
Australia boss Tony Popovic admitted his side were second best for large parts of the contest, particularly in the opening 45 minutes.
"I don't know if it was the occasion but we looked sluggish and heavy-legged. They were quicker and more powerful. They won every duel and every second ball. When they do that it makes it difficult to gain any momentum," Popovic said.
"We conceded two soft goals but I thought the reaction second half was outstanding. Against the noise here, the host nation, the players showed how good they were in the second half but you can't give away that much in the first half at this level."
Popovic suggested changes could follow for Australia's next fixture.
"Every game is different. We had a lot of fatigued bodies in the first half both physically and mentally. The second half was outstanding and we have to build on that," he said.
He also touched on the officiating.
"I wouldn't say today was the best day for the referees, but overall we weren't good enough in the first half. You've got to hand it to them, they are very strong," Popovic said of the USA.
Pochettino was full of praise for his side's display, despite the absence of his talismanic captain.
"I think it was a fantastic game again, very good first half. I think we dominated the game against a very tough team. When the draw happened in December I thought it was really difficult, a really tough game," Pochettino said.
The Argentine also reflected on the support inside the stadium.
"Amazing. I was saying yesterday Argentina have amazing fans but I think we are matching Argentina. Our fans, I'm so happy for them," he said.
Pulisic missed the match through a calf injury picked up in training during the week, with Ricardo Pepi stepping into the lineup in his absence. Pochettino addressed the difficulty of competing without his captain.
"Always difficult because we want to have all the players fit. He's an important player for us but that is a team. It was impossible for him today to play. We hope that next game he will be available but if we want to win the competition we need the whole team," Pochettino said. "All of the players need to be important but of course Christian is one of the best players in the world and I hope that he can recover as soon as possible and can show it on the pitch and help the team."
The result puts the United States top of Group D, with their qualification for the last 32 already secured ahead of a final group game against the winner of the playoff path involving Turkey, Romania, Slovakia and Kosovo. Australia must now regroup quickly and find a response to a first-half performance their own head coach described in unflattering terms.