The QPR striker only made his international debut for Northern Ireland last month, and followed that up with his first goal in the 1-0 win over Slovenia this week.
The 23-year-old charged his way through the defence before firing past Atletico Madrid goalkeeper Jan Oblak to hand his side the win.
The result means Michael O’Neill’s side have now gone ten games unbeaten for the first time ever, capping off an impressive home debut for Washington.
And Sinton praised him on Twitter, saying his goal bodes well for QPR in future.
Washington will now be hoping he can finally break his league duck for Rangers between now and the end of the season.
He has currently gone eight games without a goal since joining from Peterborough United in the January transfer window.
His first international goal should give him some confidence when he returns to Lotus Road after the international break though.
Given Northern Ireland aren’t exactly blessed with strikers either, there are certainly places up for grabs for Euro 2016, and he will be keen to make one his in the games remaining.