New Zealand internationals Tim Brown and Ben Sigmund both got on the scoresheet for the Phoenix before the home side bounced back with two of their own goals.
Coach Ricki Herbert was happy with the result in difficult conditions.
"The conditions were very hot and humid and that told towards the end of the match," Herbert said.
"We started very, very well and had them under a lot of pressure and were very comfortable, but it was clear we were tiring somewhat as the clock wound down, and Tianjin were able to take advantage.
"Still, this was a very pleasing result and great preparation for the season ahead. We were able to give everyone in the squad some game-time against a very competitive top-flight side and that will be very beneficial for us."
The Phoenix will next meet Guangzhou on Tuesday in the second match of their China tour.