Smalling struck with a powerful header in the triumph in Hong Kong.
"It was difficult, all of the games have been difficult in this heat but it will hopefully stand us in good stead during the season," Smalling told MUTV. "It was nice to pop up with a goal too. But to be fair, I probably should have got a hat-trick. Hopefully, I will get more chances like that.
"I was waiting for it (the goal), I have been due one because I didn't get too many last season. Hopefully, I will be able to get a few more this season and chip in a little more."