A total of 19 wickets fell on a fast-moving Tuesday at Chelmsford, with the Bears 17 runs in front with one wicket remaining of their first innings.
Earlier in the day, Bamber continued his outstanding form by taking career-best First Class figures of six for 26 as they bowled the hosts out for 134.
On a testing pitch, the Bears ended the day on 151 for nine, with Sam Hain unbeaten on 58 at the close of play.
“It was a fast-moving day,” Bamber said. “Good for the neutral.
“I think it’s fair to say a little opportunity may have escaped us there to impart a bit of a bigger lead, but any lead is good.
“Sam [Hain] batted so brilliantly, and Olly [Hannon-Dalby] in the morning will try and extend that as long as possible and then we’ll get back to it with the ball.
“I think we have good faith in where we are and it’s excitingly poised.”
Bamber’s figures of six for 26 saw him go past 100 wickets for the Club in only his second full season.
The 27-year-old was quick to praise the full bowling unit, with today marking the fifth innings a row where the opposition have failed to reach 160.
“It’s great to be part of,” he added. “I think we’ve spoken a lot through the year about operating as a unit and about complimenting one another, and recognising when there’s moments to hold and when to be aggressive.
“I think people have really bought in to that throughout the year and rewards are coming. There are so many things that go into a bowling performance.
“I’ve also got to mention the catching behind the wicket as well all year. I think Yatesy [Rob] has more catches than anyone.”
With the game evenly poised, Bamber is hoping that Hain can continue his fine form by adding a few more to the total when play resumes at 10:30am tomorrow.
“There was a little bit in it [the pitch],” he said. “With the 10:30am start, there’s a bit of moisture and it seemed a bit tacky early on. There was a heavy breeze which helped the swing nicely.
“He’s [Sam Hain] just class. On a difficult pitch, with wickets falling around him, time and time again he is the standout batter. He finds a method and finds a way.
“He’s so skilful and so clear on how he goes about it. It’s a great lesson to all of us and we’re very lucky to have him.”
Day two gets under way at Chelmsford at 10:30am on Wednesday 16 September.