Brentford head coach Thomas Frank admitted his team had to learn a lesson after they allowed a two-goal lead to slip as Derby fought back to earn a 2-2 draw.
It was no surprise when they scored a second in the 23rd minute, with both Toney and Mbeumo involved in the move that Sergi Canos finished with a low drive from the edge of the box.
Derby had to respond and they did with manager Wayne Rooney making three substitutions which changed the game.
Frank said: "Definitely a game of two halves. I thought we were absolutely excellent first half, maybe one of the best we've played so far in the season, totally in control on and off the ball and could have been up by more than two.
"We talked at half-time of needing to up the tempo, we knew they would come flying out, they changed three players so we knew something would happen.
"Then they got that goal after one minute so now it's a master-stroke by Wayne and his coaching staff and was well deserved. I think definitely they deserve some respect because they did what they did to change things.
"But after we got out of the first 15 or 20 minutes we need to do better, we simply didn't keep the ball well enough. Now we need to move on and take the best bits from the first half and learn from the second half."
Rooney said: "The first half was everything we didn't want. We looked a bit nervous and if you leave teams like Brentford that space they'll hurt you so I had to make changes at half-time.
"We showed great energy and great character and fully deserved a point in the end. We came out at half-time and played with no fear. I know sometimes it's difficult to do that but that's what we have to do, we have to believe we are a good team.
"If we play on the front foot, are aggressive, take chances and are not scared of the consequences then we'll do well. The second half was very good and had Brentford on the back foot."