The decisive score came after 25 minutes when the Samoan centre barged his way in at the far corner following a break and long, looping pass from Ludovic Mercier.
Although Fanolua had Simpson-Daniel outside him, he was strong enough and direct enough to power home. It was the crucial moment in a scrappy but hugely physical encounter that pushes Gloucester back into third place.
It was not a thing of beauty - particularly after Gloucester stopped playing with a fluency and invention after 30 minutes and began kicking away possession in the second half. Up until four or five phases, they looked a thoroughly dangerous side, especially when possession was cleared quickly from the contact area, but after that they had to begin all over again and it deprived them of momentum against a side who threatened only occasionally.
But Gloucester could be thankful for the contributions of Alex Brown, outstanding in the second row, Jake Boer, the flanker who was always prepared to carry ball and make tackles and Andy Hazell - truly at home on the openside flank.
Gloucester found themselves 3-0 after 17 minutes when Matt Burke kicked a penalty but they always had more invention and ideas than Newcastle and after 25 minutes, they scored.
It was a very simple score but beautifully created. Terry Sigley and Alex Brown crashed ball into midfield before Mercier straightened the attack and his long pass was plucked out of the air by Fanolua, who powered in at the corner for the opening try.
Gloucester continued to dominate and both Simpson-Daniel and Peter Richards were both heavily involved in a series of attacks that took the visitors to beneath the posts.
Newcastle, with Mike McCarthy and Colin Charvis heavily involved, defended valiantly through a series of powerful phases and when the ball came left, Gloucester coughed up possession and Tom May gathered.
He had the length of the field in which to run but Rudi Keil got back to cover the danger and prevent a Falcons score right on half-time. But he was penalised for killing the ball and Burke landed the three points to leave Newcastle trailing 7-6 at the break.
After the interval, the contest lost all pattern and structure. Simpson-Daniel had one little break and Fanolua kicked diagonally for James Bailey to chase but once Gloucester stopped playing, Newcastle roared back into the contest.
They threw themselves into the contact area, attacked the scrum and went for it in the line-outs. It reduced Gloucester to their component parts and it meant the visitors kicked away plenty of possession as they sat back on their lead.
The longer the game went on with only a point difference, the more Newcastle grew into the contest. With Jamie Noon now on and Mathew Tait always threatening in midfield, Newcastle sensed a way back into the game.
However, the clash was well into the final quarter when Newcastle took the lead. Mike Tindall was penalised for off-side and Burke slotted the three points to hand the home side a 9-7 lead.
The score shook Gloucester up. Immediately from the re-start they at last attempted to play some rugby and won a penalty that Mercier slotted comfortably to re-establish their lead.
With time ticking down, Gloucester found a second wind with the likes of Adam Eustace and Nick Wood now in the action. And from a scrum, Gloucester were awarded a penalty that Mercier clipped over to leave Newcastle requiring a try.
Penalties were now no longer good enough for the Falcons but in the last minute, they should have snatched the game. From a line-out that was driven infield, Noon came crashing through past Mercier and almost up to the line but his pass was dropped by Ben Woods and Newcastle's most threatening attacking move had come to nothing.
Gloucester closed the game out from the scrum to seal four vital and highly cherished four points. On a scrappy afternoon, it was all that mattered.