Keatley was right and wide with penalties in the 8th and 12th minutes but a superb Mick O'Driscoll take from that 12th minute restart handed possession back to Munster and after probes from first Luke O'Dea and then Paddy Butler, Connacht gladly conceded the penalty and Keatley opened Munster's account.
Turnover ball inside the Munster 22 provided the best opportunity of the opening score, Sean Scanlon using his blistering pace to race into the opposite 22 and Keatley just failed to gather his delicate chip infield.
Moments later Connacht were penalised for not rolling away and Keatley made it 6-0 but Niall O'Connor opened Connacht's account almost immediately after with a penalty from the ten metre mark.
Then a cracking try followed by an awful error left Munster in the driving seat.
First it was a move starting with Simon Zebo then Keith Earls whose superb quick hands released Luke O'Dea who in turn took a good line before passing inside for Scanlon to step full-back Duffy and score on the right at the Ballynanty end.
Minutes later the action turned to the far end where Fetu'u Vainikolo failed miserably to deal with a bouncing ball with Tomas O'Leary reacting sharply to get the touchdown that took Munster into the break leading 18-3.
Keatley and O'Connor swopped early second half penalties before Earls and O'Leary got their wires crossed to put their side under pressure but Mick O'Driscoll took cleanly at the five metre throw and O'Leary eased the pressure with a clearance to the 22.
Defences were on top in the second half with the scores coming via the respective boots of Keatley and O'Connor.