History repeated itself for Gomes as the Brazilian became the first goalkeeper to save two penalties in two Premier League games.
He first achieved the feat playing for Tottenham against Sunderland in 2010, saving twice from Darren Bent.
Gomes conceded the first penalty against West Brom, tripping Berahino in the area, after the striker latched on to a through ball from Stephane Sessegnon.
But Gomes dived to his right to save the 22-year-old’s shot.
Then 20 minutes later, Sessegnon was brought down by Etienne Capoue, and Berahino once again stepped forward to take the spot kick.
This time Berahino shot to the bottom left corner, but with little power, and Gomes was there again to save the day for Watford.
Perfect preparation for Watford
In eight days’ time Watford face Crystal Palace at Wembley for a place in the FA Cup final.
Manager Quique Sanchez Flores had warned his players against becoming distracted by their trip to Wembley, but they put in a composed performance at The Hawthorns.
Flores made four changes from the side that drew 1-1 with Everton last weekend but he was still able to field a strong starting XI with top-scorers Troy Deeney and Odion Ighalo up front.
That pair failed to see much of the ball, with just one shot on target between them.
Instead it was Watford’s rearguard effort that saw them home, defending deeply against a West Brom side who enjoyed the lion’s share of possession.
The home side struggled in the final third and the two penalties aside, it was Gareth McAuley who had the best chance early in the second half, seeing his header was tipped over the bar by Gomes.
Man of the match – Heurelho Gomes
Gomes told BBC Radio 5 live: “I did the same against Sunderland [in 2010] but that was a different feeling as we lost the game. This means a lot – it is great for me and most importantly great for the club.
“There is always more responsibility on the player taking the penalty than on me. He has the possibility to shoot anywhere and I need to be prepared to react quickly.
“I always try and wait for the penalty taker’s decision. I never think about what he will do, I just waited for him.”
What they said:
West Brom manager Tony Pulis: “It’s a cruel game at times. I thought we played really well today – 40 crosses, two penalties – but it was just not our day.”
“Good strikers miss penalties, and Saido is a good player – this will only make him better and stronger. He just has to bounce back. The players have been great with him and he will feel it as much as anyone.
“Saido wanted to take [the second penalty], and some top, top players have missed penalties, players who have had the nous to take the next one and that is what Saido did. I hope if we get another penalty in the next few games he is the one to smash it in.”
Watford manager Quique Sanchez Flores: “It was strange match – not too much football and both teams did not play really well.
“I’m not sure if we have enough points but what is most important is that we have to keep improving. It’s creating a very good atmosphere around the team and will be important for the next match.”
Watford have a trip to Wembley on Sunday for the FA Cup semi-final at 16:00 BST. The Hornets’ next Premier League game is against relegated Aston Villa on 30 April. With 41 points, Watford look sure to play successive Premier League seasons for the first time.
West Brom, who are on 40 points and also look safe, face a trip to Emirates Stadium to play Arsenal in the league on Thursday evening.
The stats you need to know:
Saido Berahino became only the fourth player to miss two penalties in a Premier League match.
Before this match, Berahino had scored all five of his penalties in the Premier League for West Brom.
Watford have now won twice as many Premier League away games this season (six) as they did in their previous two Premier League seasons combined.
Ben Watson (two) is only the third player to have scored more than one goal for Watford in the Premier League this season.
This was Watford’s first league win over West Brom in 16 attempts (W1 D7 L8) and their first league win over them since February 1995, a game that also ended 1-0 to the Hornets at The Hawthorns.