It wasn't just the 24-year-old's first try of this campaign but only his second in the league in Ospreys colours - his only other score coming in the 2009-10 season.
And while keen to convey the team effort needed to get one over the current leaders, Humphreys insists he always had faith in Bevington, even if others didn't.
"When that ball reached Ryan Bevington I was never in any doubt that he was going to score, I knew that no-one would catch him," he said.
"As well as being a good scrummager and good in the park, we know at the Ospreys that he's got a turn of pace as well.
"The only frustrating thing about him is that sometimes when he is only average, we know that he has that kind of performance in him.
"It was an unbelievable effort from the whole group. It was truly remarkable and I'm so, so proud of everybody involved here.
"The spirit, the effort and the determination was second to none and that was typified by the spell when we were down to 14 men after what was an incredibly harsh yellow card and we ended that period leading for the first time.
"It was a huge team effort and everyone can enjoy this. Ulster are an outstanding team as we know and they had real quality on the pitch but we were deserved winners."