Match ends, Swansea City 0, Brentford 3.
Brentford claimed an emphatic 3-0 victory at Swansea City as the Welsh club's home struggles continued.
Thomas Frank's team are celebrating back-to-back victories for the first time this season after turning on the style in south Wales.
Said Benrahma claimed his first goal of the campaign to give Brentford the lead, the Algerian sending a curling shot beyond Freddie Woodman.
Griffin Park old boy Jake Bidwell's own goal meant it was 2-0 at the break and Bryan Mbeumo's ruthless finish from just outside the box sealed the victory.
Swansea are unbeaten on the road in the Championship this season, but their home form has dipped alarmingly - and Welsh rivals Cardiff City come next on Sunday.
Steve Cooper's side started this season in spectacular fashion, winning seven of their first eight games in all competitions.
But results have been much harder to come by for the Swans since Cooper was named manager of the month for August.
Swansea had not lost a home league fixture since Boxing Day 2018 until Nottingham Forest won at the Liberty Stadium in September, yet they have now taken just one point from the last four games on their patch.
Brentford's fortunes this term have been mixed, with Frank's men struggling to find any consistency.
But having come back from 2-0 down to claim a rousing last-gasp win over Millwall on Saturday, Brentford looked sharper than Swansea from the outset.
Yan Dhanda threatened a couple of times for the hosts in the first half, while skipper Matt Grimes saw a long-range drive saved.
Brentford were much more fluent going forward, though, and it was no surprise when Benrahma rounded off a flowing a counter-attack with a fine finish to give the west London club a 30th-minute lead.
Things quickly got worse for the hosts as Brentford doubled the advantage six minutes later after Kristoffer Peterson gave the ball away near halfway.
Peterson, making a first league start since his summer move from Heracles, had some bright moments going forward, but his loose pass cost his team dear as Ollie Watkins seized possession.
Bidwell did cut out Watkins' pass into the box for Mbeumo - but only succeeded in prodding the ball low past his own goalkeeper.
Swansea briefly rallied at the start of the second half, with Peterson flashing a shot just wide of the post.
But France Under-21 international Mbeumo ended any hope of a comeback when he picked off a Joe Rodon pass and netted his third goal of the season with a shot which gave Woodman no chance.
George Byers came close to pulling one goal back with a header only for David Raya to save brilliantly, while Andre Ayew and Sam Surridge both missed the target late on to round off Swansea's miserable night.
Swansea manager Steve Cooper: "It was disappointing. I am not going to hide away from a poor scoreline at home.
"If you are like that at this level you will get punished, and we have made two big errors for the second and third goals. So you go 3-0 down and it's a tough ask to get back into it.
"We particularly fell short with our defending throughout the pitch, not just in the back four and around our goal. If you do that you concede goals and we got punished."
Brentford head coach Thomas Frank: "It was close to perfect.
"We wanted to go high and press on goal-kicks and from the goalkeeper's hands to try to win the ball high.
"When we won the ball we were a big threat counter-attacking. We pressed high again in the second half and got the third goal and we more or less controlled the game after that.
"I see consistent good performances and hopefully there is more to come - but we need to keep our heads down and continue working extremely hard."
- 23RobertsBooked at 71mins
- 5van der HoornBooked at 83mins
- 6FultonSubstituted forByersat 45'minutes
- 22A Ayew
- 21DhandaSubstituted forCelinaat 45'minutes
- 9BastónSubstituted forSurridgeat 70'minutes
- 18JanssonBooked at 85mins
- 14DasilvaSubstituted forJensenat 76'minutes
- 19MbeumoSubstituted forValencia Castilloat 70'minutes
- 10BenrahmaSubstituted forZamburekat 88'minutes
- 16Valencia Castillo
- Gavin Ward
- Shots on Target
Second Half ends, Swansea City 0, Brentford 3.
Attempt missed. Sam Surridge (Swansea City) right footed shot from the centre of the box is just a bit too high. Assisted by André Ayew.
Offside, Brentford. Henrik Dalsgaard tries a through ball, but Ollie Watkins is caught offside.
Attempt missed. Sam Surridge (Swansea City) right footed shot from the centre of the box is just a bit too high.
Attempt missed. André Ayew (Swansea City) left footed shot from the centre of the box is just a bit too high. Assisted by Bersant Celina.
Substitution, Brentford. Jan Zamburek replaces Saïd Benrahma.
Attempt saved. Saïd Benrahma (Brentford) right footed shot from the left side of the box is saved in the centre of the goal. Assisted by Rico Henry.
Pontus Jansson (Brentford) is shown the yellow card for a bad foul.
Sam Surridge (Swansea City) wins a free kick in the defensive half.
Foul by Pontus Jansson (Brentford).
Mike van der Hoorn (Swansea City) is shown the yellow card for a bad foul.
Foul by Mike van der Hoorn (Swansea City).
Saïd Benrahma (Brentford) wins a free kick in the attacking half.
Corner, Swansea City. Conceded by David Raya Martin.
Attempt saved. George Byers (Swansea City) header from the centre of the box is saved in the bottom left corner. Assisted by Kristoffer Peterson with a cross.
Attempt saved. Kristoffer Peterson (Swansea City) right footed shot from outside the box is saved in the bottom left corner. Assisted by Bersant Celina.
Attempt blocked. George Byers (Swansea City) right footed shot from the centre of the box is blocked. Assisted by Connor Roberts.
Substitution, Brentford. Mathias Jensen replaces Josh Dasilva.
Corner, Brentford. Conceded by Joe Rodon.