Ben Chilwell put the Blues ahead in a tepid game that exploded in the final 20 minutes as the Bees launched a full-on assault of the visitors’ goal at Brentford Community Stadium.
While manager Frank was delighted by his team’s display at both ends, he was gutted at failing to produce a famous late strike.
He told Sky Sports: “If you look over the 90 minutes, there can only be one deserved winner: that’s us. And by quite a large margin, in terms of how many chances we created.
“We kept the European champions and first-placed in the Premier League to five shots in the whole game. That’s very impressive.
“I know they dominated the first-half a little bit but in the end we were all over them, and that’s very very impressive. So [I’m] proud of the performance, pleased, and that is what we need to build on.”
Brentford sit seventh in the table after a strong start to their Premier League debut campaign. Frank is determined to use the narrow defeat as a further confidence boost going forward.
The Dane added: “I’m just very proud, very pleased. Top performance over 90 minutes.
“They needed to win, they got a very very lucky win here today. That’s why it’s so impressive, it adds to the narrative from four months ago because they won the Champions League and we won the [Championship] play-offs.
“It’s all about the performance because if we play this game again, we’ll win. Nine out of ten. It is what it is and we really want to build on this.”