Yes, the convention in the US is to report the winning team first.
Take Wednesday's article in the New York Times on Tuesdays's Yankee-White Sox. matchup played at Guaranteed Rate Field (the home field of the White Sox).
The header reads "YANKEES 7, WHITE SOX 3," although the score isn't mentioned directly in the text.
Likewise, Wednesday's article on the Reds-Mets game (at the Mets' home field), lists the Reds first: "REDS 3, METS 1, and the copy matches.
Sal Romano got the win in his New York homecoming, pitching into the seventh inning to lift the Cincinnati Reds over the Mets, 6-1, on Tuesday night in a game delayed by rain for 1 hour 40 minutes in the first inning. [emphasis added].
I added two examples from New York home teams to show it isn't a convention to list the local team first either. I would also note that in baseball, the away team always goes first and the home team second, so it would be very normal to always list [away]-[home], although that isn't the case (see today's article on the Yankee's home win, where the Yankees are listed first).
For a soccer example, I dug up this 2015 article on the New York City F.C. vs. Portland Timbers game, which was played on NYCFC's home turf.
In this article, the Timbers (away) are listed first in the header: "TIMBERS 1, NEW YORK CITY F.C. 0 and in the copy:
Dairon Asprilla scored a late second-half goal Sunday night, and the Portland Timbers beat New York City F.C., 1-0.
Anecdotally, growing up in America, I was always taught to list the winning score first, regardless of sport. In fact, I wasn't even aware anyone did it differently.
