Gloucester will now face Saracens in the Premiership Wild Card final next Saturday, whilst Falcons stat Jonny Wilkinson is denied a return to the ground he has not graced since September, 2003.
But Lions coaches Andy Robinson and Dave Alred were in town for the game, and watched Wilkinson kick three penalties and convert fullback Matt Burke's first-half try, and the fly-half could conceivably be added to Sir Clive Woodward's 44-man squad later this week.
Emergency centre James Forrester, a back row forward switched to midfield duties because of an injury crisis, was Gloucester's hero with a try in each half, and there was also a touchdown for captain Adam Balding.
But fly-half Duncan McRae confirmed Gloucester's victory – their first at home in five games – with two late penalties after Wilkinson missed a penalty chance from 52 metres.
Injuries forced Gloucester into some radical surgery behind the scrum, where Forrester featured at inside centre after Terry Fanolua missed out with a back problem, and fly-half Brad Davies moved to full-back, as Jon Goodridge and Olly Morgan were both unavailable.
Luke Narraway, meanwhile, started in the back-row, and there were bench slots for Wales Under-21 skipper James Merriman and 18-year-old Ryan Lamb.
Wilkinson was quickly involved, shredding Gloucester's midfield defence with a weaving run, but Newcastle found themselves largely penned in their own 22 as they faced a gusting wind.
They absorbed pressure well though, and Wilkinson hoisted them ahead through his first penalty before Gloucester finally made territorial advantage tell.
Newcastle had tackled superbly, but their defensive organisation was finally unlocked on 31 minutes when the rangy, powerful Forrester held off three Falcons challengers to score a superb try that McRae converted from the touchline.
Wilkinson's second successful penalty narrowed the deficit though, and Newcastle finished the half in style when centre Mark Mayerhofler's quality approach work enabled Burke to touch down.
Wilkinson converted, before McRae missed an easy penalty chance to reduce the arrears and Newcastle led 13-7 at half-time.
Gloucester knew they had to make their presence felt early in the second period by making pressure count, and it took just five minutes before Newcastle's defence was unlocked again.
Substitute Peter Buxton, who had been on the pitch barely 60 seconds, made the initial headway in a sweeping move, and skipper Balding powered over after prop Gary Powell and flanker Jake Boer acted as link-men.
It brought Gloucester back to within a point, yet Newcastle knew they could rely on Wilkinson, and such confidence was confirmed when he completed his penalty hat-trick and gave Falcons a four-point advantage.
But back came Gloucester, setting up an intriguing final quarter through Forrester's second try that edged the home side one point ahead.
Wilkinson narrowly failed to find the target from 52 metres, yet McRae kept his nerve with just six minutes later, landing an angled penalty that confirmed Gloucester's victory.
It leaves Gloucester with at least the chance of salvaging something from their season, while Newcastle must make do with second-tier European Challenge Cup rugby next term.
For Gloucester:Tries: Forrester 2, Balding Con: McRae Pens: McRae 2
For Newcastle Falcons:Tries: Burke Con: Wilkinson Pens: Wilkinson 3