Sergeev headed home the only goal of the game in Sydney, but they needed a superb save from Nesterov to seal the win.
The goalkeeper made a stunning one-handed stop in stoppage time to deny a Pak Song-choi header, leaving Kasimov singing his praises after the final whistle.
"It was hard, [in] the last minutes, and I would like to thank Nesterov, our goalkeeper," he said. "It was great save, but it was the victory of the whole team.
"I am happy with all my players, not just the goalkeeper but as you know the goal keeper is the heart of the team."
And Kasimov went on to acclaim 21-year-old Sergeev after he looped a header beyond Ri Myong-guk, predicting a big future for the Pakhtakor forward.
He added: "I think he has a great future in club and national team, but he should not stop on this level, he should always work hard and I think he can do it and he can be one of the best in Uzbekistan."
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