After scoring a spectacular chip from his own half, which looked like a David Beckham-style chip, he had a late penalty saved as the game ended in a 2-2 draw.
Despite being second-best for most of the match,Watford took the lead in sensational style on 12 minutes when Senegalese forward Sarr took down a clearance, pushed the ball out from under his feet and coolly lifted it over the stranded David Button.
That came against the run of play,Watford keeper Daniel Bachmann having already been kept busy, with one superb save from Darnell Furlong's volley and two from Karlan Grant - and there were more to follow.
Two minutes into first-half added time, Grant scored after taking the ball down excellently and finishing right-footed.
The Hornets were on the back foot for most of the second half, yet they had the best chance to win it when Sarr went down easily in the penalty area.
The keeper swooped to save the spot- kick, which was struck far too feebly to Button's left.
Going into their next game, when they host another team with four points from two games, they have four points from two games.
The only side with a 100% record in the Championship after two games is Blackburn.
Although they have only drawn the first two matches, the Baggies have come from behind in both of them.
Although they were hampered by the loss of Dike with a thigh injury, they should still have plenty to be happy about.
As he unleashed his early contender for goal of the season with a wonder strike that drew comparison with any other goal in this very limited genre, sarr stole the show and made all the headlines.
A young Beckham's entrance on to football's big stage, with that amazing effort at Selhurst Park in August 1996, may be the best one.
The 1995 European Cup Winners' Cup was lost to Real Zaragoza by just ahead of similar pieces of brilliance.
None of them netted from more than 60 yards and then missed from 12 yards in the same game.
The missed penalty was just as bad as the goal because it was so bad.
Steve Bruce is the head coach of West Bromwich.
Sometimes you don't get what you deserve, but that's as good as I've seen us play and to do it against such a good side made it even better.
It's very frustrating that we didn't win but it was still a great reaction from the players after they conceded a wonder goal.
"Daryl Dike has a thigh injury and is out for the season." He wanted to play for his country at the World Cup and he knew as soon as he did it.
The manager ofWatford told the British Broadcasting Corporation.
It was an amazing strike from the man. I knew it was in when he left.
There was a moment of brilliance. When you see a goal like that, it's pretty special.
If we had gotten the second goal from the penalty, it would have been unjust as they were the better team. I would have accepted it.