The key reason is that Zhang Hao plays an off-ball style, and the current rule that doesn't allow early double-teaming is very advantageous for Zhang Hao's style. This is directly related to Zhang Hao being able to consistently score high since entering the NBA.
The Blazers have to wait until Zhang Hao receives the ball to double-team him, and with the requirements for overall defense, it's really difficult to stop Zhang Hao who is determined to shoot.
The key is that Zhang Hao's shooting touch is really good tonight, even with a lot of troubles, he prepared well before the game.
The Lakers didn't defend well at the start, as Nash showed good performance with his skills, speed, and stamina, making it not a big problem to play against Kenny Anderson or Doug Christie. If a young guard is given the chance to get going, it can be very troublesome. The Lakers want to win, just like the Bulls with Jordan scoring, they won.
