A goalkeeping blunder by Bartosz Bialkowski gifted the hosts the lead when Toumani Diagouraga's tame side-footed effort slipped through his grasp and rolled in.
The stopper was substituted at half time but there was little his replacement Kevin Pilkington could do to stop Brentford making it two on 70 minutes through Bradley Wright-Phillips.
Brentford were pegged back minutes later when Jake Bidwell sent Alan Judge tumbling inside the box and the Magpies midfielder reacted quickest when Jamal Campbell-Ryce's hotly contested spot kick was saved by Simon Moore.
Kiwomya said: "I'm disappointed really because in the last 15 minutes we were easily the better side. Brentford coped far better than us in the early stages but by the end they had changed their system and were wasting time."
Explaining the half-time substitution of Bialkowski, Kiwomya added: "He has been struggling with a virus and was a doubt but he wanted to play. He has shown that he is a top keeper so I have no problem with him whatsoever. The fact is we play as a team and I was very happy with the spirit we showed."
- Sports & Recreation
- Bartosz Bialkowski
- Jake Bidwell
- Toumani Diagouraga