Now Wales star fly-half Hook reckons the Ospreys are capable of tasting success in Ireland again by toppling the reigning champions at Thomond Park.
Hook, 23, said: "We can definitely beat Munster. It's the biggest game in our history and we've got the chance to go and turn over the reigning holders of the Heineken Cup in their own backyard - it's a huge game for us.
"Ulster have beaten Munster twice this season but we were able to do the double over them this season so that gives us an advantage.
"Hopefully we can also get revenge over the Irish for what happened in the Six Nations and make it one-all. The prize is a home semi-final and securing that would be fantastic."
The star-studded Ospreys have the chance to deny Munster a league and European double this season.
And Hook - who scored 11 points with the boot in Belfast - reckons the Ospreys have proved they have the bottle and mental strength to claim silverware.
Hook said: "Winning at Ravenhill is a massive boost for us because I remember losing there by 40-points two years ago - that was demoralising.
"Ravenhill has been a fortress so the result has shown everyone how far we've come.
"It was a hugely important win not only for our league hopes but to regain our confidence from losing in the EDF Energy Cup semi-final."
Hook is in the last chance saloon to impress British Lions coach Ian McGeechan before he announces his squad to tour South Africa this summer on April 21.
The 33-cap Wales star faces a battle royale at number ten with Ireland Grand Slam hero and Lions rival Ronan O'Gara. But Hook insists he is ready for the challenge.
Hook said: "My kicking wasn't great against Gloucester but I worked really hard and was happy with the way I bounced back against Ulster.
"We dominated the game but suffered a setback when we conceded a late try. But we showed real bottle to fight back and win.
"It was a real team effort and that paid off in the end. Hopefully we can take that confidence into the game at Munster."