The stand-in skipper's brilliant unbeaten 139 underpinned a 41-run win over UAE at the Bert Sutcliffe Oval, as the Scots became the first side to win the tournament (formerly the ICC Trophy) for a second time.
They last lifted it under the captaincy of Craig Wright, currently the joint interim coach and now a front-runner to land the job on a permanent basis.
Last night, though, Wright was more concerned about emphasising the potential of a team he believes can more than match the achievements of his ICC Trophy-winning team of 2005. Wright said: "Qualifying for the World Cup and winning this tournament can be a real coming of age for this team. It's a fantastic achievement and the quality of the cricket they have delivered under pressure has been outstanding.
"It has been great to see so many different individuals step up when required. The players have shown tremendous character and mental strength to achieve this success, particularly considering the disappointment of missing out on the T20s before Christmas. They deserve tremendous credit.
"Hopefully this is just the start for this group who are young enough to grow together as a team and achieve further success. Qualifying for the World Cup is only a stepping stone for what this team are capable of doing."
The character Wright spoke of was called on as Scotland recovered from a dreadful start after winning the toss and electing to bat. When Calum MacLeod, the scorer of two centuries in the group stages, went for a duck and was followed in quick succession by Matty Cross and Matt Machan, lesser sides might have panicked on being reduced to 37-3.
Instead Mommsen, with good support from Freddie Coleman, eased his side's jitters before giving them a sense of total control. The pair added 91 for the fourth wicket before Coleman was bowled by UAE captain Khurram Khan for 31.
A platform had been created and Mommsen, then joined by Richie Berrington, took full advantage. Mommsen went on to post 139 from 149 balls with a dozen boundaries and a single six while Berrington contributed a hard-hitting 63 from only 53 deliveries. Their 138-run partnership allowed Scotland to post 285-5.
The recovery served to deflate the UAE who were never up with the required rate. Nor did the Arab batsmen look comfortable against the pace of Rob Taylor, Iain Wardlaw and Safyaan Sharif who claimed three wickets apiece.
Mommsen, voted man-of-the- match and player-of-the-tournament, said: "This is what dreams are made of. We had huge goals coming here and we've made it, so we have so much to look forward to and a lot to prepare for."
The stand-in skipper was referring to the reality of ties against co-hosts Australia and New Zealand and a first World Cup clash with England. The Scots will also face Sri Lanka, Bangladesh and Afghanistan.
Mommsen added: "We're going to play some of the best teams in the world, but there will also be opportunities to get some wins, and cause a couple of upsets. It's an awesome prospect. Obviously England will be huge for us."
Result: Scotland 285-5 (P Mommsen 139no, R Berrington 63, F Coleman 31; A Guruge 3-67) beat UAE 244-9 (S Patil 99no, A Ali 34, K Khan 34; S Sharif 3-41, R Taylor 3-48, I Wardlaw 3-58) by 41 runs.