Mark Bowen’s unbeaten start as Reading manager came to an end as Ollie Watkins’ second half header condemned the Welshman to his first defeat in charge of the Royals.
Reading drop one place to 18th in the Championship table after losing their first game for five matches.
Neither side created many clear cut chances in a tight game with George Puscas missing Reading’s best chance of the match after he went through one-on-one in the first half as Watkins stole all three points for the hosts with the only goal of the game in the 61st minute.
With a sell out crowd making the short away trip to Griffin Park for Reading’s last league visit, the game got off to a slow start with an early stoppage in play which saw Brentford temporarily reduced to 10 players.
Reading were looking to make it five consecutive games without defeat as Mark Bowen named an unchanged line-up from the Royals’ 3-0 triumph against Luton Town before the international break.
Royals full-back Andy Yiadom picked up an early yellow card just three minutes into the contest as both sides struggled to find any rhythm to their play in the heavy rain conditions.
Rafael reacted slowly from a Michael Morrison back pass and was relieved to see the ball fall behind for just a goal kick instead of the back of his net as his clearance bounced off Brentford forward Ollie Watkins.
Watkins proved to be the Bees’ bright spark in attack as he drove into the box, but Morrison did enough to nick the ball away from him before Andy Rinomhota mopped up in defence to clear from danger.
John Swift picked up the second yellow card of the game before Yiadom flew into a tackle on the halfway line and was fortunate to stay on the pitch as the referee decided against giving the right-back a second caution.
Reading then had the best chance of the half with just over half an hour played. Yiadom looped a ball over the top to find George Puscas who raced through one-on-one with David Raya, but the striker took a wayward touch to narrow the angle as he tried to push the ball past the keeper as the chance went begging.
Rafael had to stay alert in between the Reading posts as he tipped a deflected shot around the post after it skidded off the wet surface, with the hosts having a few corners in quick succession at the end of the half.
But a quiet half came to a close as the sides went in level at 0-0 with clear cut chances few and far between.
Bowen made an early change in the second half as Sam Baldock was replaced by Yakou Meite after picking up a knock.
Ovie Ejaria produced a trademark piece of skill to beat two Brentford defenders and break into the box, but his cross was eventually cleared out of danger from the home side.
Bowen then opted to make another change with half an hour of the second half left to play as Puscas was replaced by Garath McCleary.
Brentford broke the deadlock in the 61st minute as Watkins bagged his 11th goal of the season by heading the ball past Rafael from close range after meeting Mahias Jensen’s cross.
The Welsh manager then made an attacking change as Reading looked to get a result from the game as forward Lucas Boye replaced Rinomhota.
Boye made an instant impact as he played a good pass to create a chance but McCleary hit his shot just wide after a cut back.
All of Reading’s attacking changes made a positive impact on the game compared to the lacklustre performances of Puscas and Baldock, but they weren’t able to get on the scoresheet as the Royals failed to find the back of the Brentford net.
Reading face Leeds United at the Madejski Stadium on Tuesday evening before they travel away to face Wigan Athletic next Saturday.
Brentford: Raya, Dalsgaard, Jansson, Pinnock, Henry, Mokotjo, Jensen, Dasilva, Mbeumo, Watkins, Benrahma.
Subs: Thompson, Daniels, Bech Sorensen, Zamburek, Racic, Oksanen, Rasmussen.
Reading: Rafael, Richards, Miazga, Morrison, Moore, Yiadom, Swift, Rinomhota (Boye 71′), Ejaria, Puscas (McCleary 60′), Baldock (Meite 50′)
Subs: Walker, Gunter, McCleary, Boye, Meite, Blackett, Pele.