The teenage tyro somehow weaved a way to the posts after picking up a loose ball and led the Blue & Black defence a merry dance before touching down for a score that built a 14-point lead, and then added a second at the end to complete 34-13 win.
But it was his stunning solo effort, the third home try of a compelling second half performance from the reigning champions, that kept his side on course for a potential league and cup double.
Cardiff head coach Steve Law promised there would be an edge to the game after losing to the Drovers in last season’s final at the Arms Park, and his side certainly rose to the occasion as they attempted to extend his reign in charge to one more game.
They led 10-6 at the break after putting the home side under intense pressure for a 10 minute period before snatching the first try of the game. Their defensive action also frustrated the normally free-flowing champions.
But two deadly strikes in the 53rd and 56th minutes suddenly turned the game on its head as the Drovers exploded into action. Whereas Cardiff had dominated the second quarter, so the home side turned up the heat in the third.
Two Jack Maynard penalties gave Llandovery an early lead before Arwel Robson got one back for the visitors. Then the relentless pressure from the Blue & Blacks pack earned them a vital try from inspirational skipper Morgan Allen in the 31st minute.
Robson added the extras, and it was Cardiff who led at the break against the side that last month beat Merthyr to win the WRU Premiership Cup and who topped the league at the end of the regular season.
But tries from outside half Ioan Hughes and replacement wing Kian Abraham in a three-minute purple patch suddenly put the Drovers firmly in charge. The first came after a driving line-out got the home side up to the line before Hughes was sent through a gap.
Having converted his own score, Hughes then improved Abraham’s score after Lee Rees and Osian Davies had paved the way for him to run in from 20 metres.
Cardiff hit back with a Robson penalty and then almost broke clear, Harri Doel pulling off a magnificent tackle to bring down Tom Habberfield on his 22. Moments later, Page was speeding away for his spectacular try.
He went on to score another before the end to complete a dramatic second half transformation that earned the Drovers a home game in the final against Newport next weekend.
The only downside for Llandovery is that skipper Jack Jones was carried off on a stretcher in the 71st minute with what looked like a serious injury that saw him receive 10 minutes of treatment on the field.
Scorers: Llandovery: Tries: M Page 2, I Hughes, K Abraham; Cons: I Hughes 4; Pens: J Maynard 2. Cardiff: Try: M Allen; Con: A Robson; Pens: A Robson 2
