Keatley and company could be excused for allowing the excitement to get to them prior to referee Alain Rolland's final whistle at a packed Sportsground.
At the clock ticked towards the 79th minute, Keith Matthews had just put in an excellent man-and-ball tackle on Mick O'Driscoll, forcing a penalty which Connacht understandably took their time over.
The preceding few plays has seen Niva Ta'auso, Frank Murphy and Ray Ofisa produce some vital tackles as Munster sought out a late try but Keatley's 12-point salvo proved to be enough as Troy Nathan hammered that late penalty to touch and Rolland blew for full-time.
The pitch was invaded and Michael Bradley and his players were duly feted, with Connacht's 22-year wait for a senior win over Munster finally at an end.
There were heroes aplenty for the home side but Ireland 'A' international Keatley showed poise beyond his years to kick Connacht into a winning position, just as he successfully managed against Leinster at the same venue in October.
The 21-year-old, known as 'Keats' or 'Drizzle' to his team-mates, agreed that all the hard work had paid off when speaking to IrishRugby.ie afterwards.
"We're all over the moon. Back in the changing room, you can't take the smile off anyone's face! It's another great win for us," beamed the man-of-the-match.
"We had our minds set on this game. We were back in on Stephen's Day - no turkey or drinks on Christmas Day!
"We knew that we had a job to do against the Heineken Cup champions - Munster are a superb team and they showed it tonight.
"But our defensive effort tonight - the forwards played amazing and we just managed to get a nice win.
"It's a huge result for our province. It's amazing to get wins against Leinster and Munster, two huge teams.
Therein lies the main source of frustration for Connacht this season. One week they are on the end of heavy defeats to the Scarlets, Cardiff and Ulster, the next they are beating Leinster and Munster and scoring bonus point wins in Europe.
Their search for consistency is an ongoing one. Certainly they are a much better outfit than their current Magners League position of tenth suggests.
Including pre-season and friendly matches, they have won seven of their 12 games at the Sportsground since August.
It is away from home that they are really struggling for confidence and form and backing up this historic result against Munster with a similar level of performance at Leinster next Friday is their next challenge.
Keatley added: "We've got Leinster down at the RDS this coming weekend. It'll be another huge game, they'll be gunning to beat us because we beat them up here.
"It will be tough. We've got to focus more on our own game and maybe we can beat them again."
From a personal perspective, Keatley, a Grand Slam winner with the Ireland Under-20s in 2007, was delighted to see his kicks go over against Munster and is hopeful that he can continue his strong place-kicking form against his native province.
"That's what I practice for - that's my job just like the hooker has to throw the ball in," the Dubliner said.
"That's my job and thankfully I didn't miss any kicks tonight."
He also paid tribute to the capacity 5,000-strong Sportsground crowd who really lifted Connacht during the tightly-contested second half.
"When you hear cheers of Munster being overshadowed by cheers of Connacht, it's really something. They were great tonight and I'd just thank all the supporters for coming."