Not sure how Zverev lost momentum in the third set but it was not all about Thiem winning, it was also about Zverev not taking his chances, Zverev served for the championship and both players also broke each other in that all important fifth set.
Well done to both players
Nice win and nice comeback for Thiem, he deserved the victory! Lets hope, he can take some next steps and also win the French Open (against Nadal).
If I am correct, there was only 1 positive Covid case in the US Open, which is very good. This shows that with good organisation and with the correct safety measures, you can safely organize big events.