Needing one run to win from the final ball, the Steelbacks secured victory thanks to a four from Keogh.
The nerveless batsman also hit the winning runs in last year's NatWest T20 Blast final success against Durham Jets and against the same side last Sunday.
He is making quite a habit of stepping up when it matters most for the Steelbacks, and Ripley was delighted with the 25-year-old's contribution once again.
"Rob's developing, he a fine young player all round," the Steelbacks head coach said.
"He's got a lot of ability and he was kind of the next man into the team last year when we started the competition.
"He's putting the gauntlet down to say 'I'm going nowhere'.
"Finals day was impressive from him last year and today it was a real high quality innings under pressure.
"I thought he was great."
Birmingham Bears had got off to a flyer at Edgbaston, with skipper Ian Bell (50) and Sam Hain (30) putting them in control.
But the Steelbacks fought back superbly, with spinners Tabraiz Shamsi (2-24) and Graeme White (2-30) pegging the Bears back as they finished on a below-par 156 for four.
And after Adam Rossington rifled 34 from 20 balls and Josh Cobb top scored with 48 from 46, Keogh got the Steelbacks over the line with a superb unbeaten 41.
"It's the year of the cliffhanger - every game seems to be taking us to the wire," said Ripley, who has seen his side win two of their first four matches in this season's T20 competition.
"As ever in T20, it ebbed and flowed. They were a little bit ahead and we pulled it back. They got going again, but we bowled really well towards the end of the innings to keep it to a score I thought we could get.
"They obviously had no Rikki Clarke to bowl (due to a hand injury sustained while batting), which was a plus for us and we made the most of it.
"Adam Rossington came out of the blocks quickly, Josh Cobb kept it going and then Rob Keogh at the end stayed calm and scored at a very good rate to get us a win.
"There were times in that chase where I thought it wouldn't be as close as some other games because we had little windows where we could have just stepped on the gas and got ahead of the game.
"We kept losing a wicket and Warwickshire kept fighting in front of their supporters so it was a last-ball thriller.
"I was confident Rob was going to get it, the way he was hitting the ball.
"I thought we'd win when it got to the last ball."