back-to-back world champion in this event. He's going to be very difficult to beat. Disken will need to pull out a big swim if he's going to come close to getting the silver he took in Rio. Barlaam slow off the start of blocks, as you suggested. Hill got a good start. But Tarasov looks the fastest right now. Well, maybe - it may be Barlaam looking to come back. Barlaam coming to the wall is going to touch Paralympic record time. Jamal Hill does medal for the United States, a good start to put him in good stead. Going sub 25 was Tarasov, but still unable to beat Simone Barlaam. The Italian has a fifth gold medal of these Games for Italy in the pool. What a swim! Tarasov goes sub 25 as he, too, dipped below the previous Paralympic record of Matthew Cowdry's. My word, Tarasov knows he was as quick as he could have been without managing to beat Barlaam. A big congratulations. For Jamal Hill, what a way to make your Paralympic Games debut. >> Yeah, I mean, Jamal Hill, that was unexpected by him. This is always what happens in the 50 freestyle. It's anybody's race, it's one length, every tenth of a second counts. >> For a moment Tarasov looked to be pulling away when - he just had a spike in energy midway through the pool but maybe noticing it and edging up a gear, Simone Barlaam just pulled away. >> Barlaam does not have the best start, but where he's really strong is - look at this wing span, look at every one of his strokes. Here he is, edging out Tarasov. They seem to be going stroke for stroke but it's Barlaam's finish where he's able to distinguish himself. He was probably hoping to break the world record, but the Paralympics, the final swim is not about the record typically, it's about getting your hand on the wall first. >> So true, Jamal Hill and Simone Barlaam timed their stroke nicely.