Wariner looked very strong in the race, which was run under fairly ideal conditions -- temp in the mid-70s and only a light wind.
Wariner, running in lane 4, had made up the stagger on Williamson in lane 5 coming out of the first turn. I don't know what his 200 split was, but he was out clearly leading the field. He had a substantial lead coming into the homestretch and held his form well to run what may be one of the faster times this year. It still wasn't a meet record, though; Michael Johnson ran 43.75 back in 1997 or 1998.
Williamson closed very well over the last 150 to pass a number of runners. And 44.88 isn't a bad start for him at all.