However, in their eagerness to win the game, Gloucester turned the ball over in their own half and Scarlets winger Aaron Warren scampered clear down the left wing to clinch the game.
It was harsh on Gloucester who had battled ferociously throughout the game, and overcome the blow of conceding a soft score to take the lead.
In fact, at that point, Gloucester looked a good bet to kick on and win the game. The defence was still robust, the pack competitive and, Billy Burns who had switched to fly half, was kicking beautifully out of hand.
But the home team just had enough savvy to eke a penalty and edge back in front before Warren's effort brought proceedings to a close.
Defeat, of course, brings disappointment. However, when this young side look back on their commitment this evening, they will do so with a sense of pride.
It was a damp and drizzly night in West Wales as kick off time approached, a night reminiscent of so many Anglo Welsh encounters from years gone by.
A minute's silence to mark the passing of Scarlets legend Hefin Jenkins was impeccably observed.
The home side dominated possession in the opening exchanges, but the Gloucester defence was disciplined and held firm through multiple phases.
The Cherry and Whites had a couple of early forays into home territory, Jonny Bentley looking lively, but ball retention was difficult in the conditions and turnovers frequent.
In fact, as the 20 minute was reached, there hadn't been a scoring opportunity of note with neither side able to gain the ascendancy in any facet of the game.
One shining light though for the Cherry and Whites was scrum half Tavis Knoyle, who was tearing around against his former club, and had put in a couple of superb tactical kicks.
The half hour mark came and went with still no score, but there was a worrying moment for Gloucester as Bentley was taken late after kicking ahead and went down clutching his knee, only to continue gingerly after treatment.
However, Gloucester did lose their skipper for the night Will James after a blow to the head and he was replaced by Jonny Hill.
As Gloucester reorganised, the first score came after 37 minutes, to the home side, and it was a slightly fortunate one.
A spiraling up and under wasn't defused by the Gloucester back three, and bounced kindly for full back Jordan Williams who put Steffan Hughes into the corner for a 5-0 lead.
Half time arrived with the Scarlets holding on to their narrow lead, although the likes of Ludlow and Moriarty were carrying powerfully in a bid to get Gloucester back into the game.
It had been a dogged, determined effort from the young Gloucester side who were refusing to take a backward step. They'd lost their skipper and talisman but were digging deep and wearing the shirt with pride.
There wasn't much happening in attack, but that was hardly surprising in the conditions, and applied to both teams in all honesty.
To get back into the game, Gloucester needed to maintain the intensity and try and play the game in the right areas of the pitch. The experience of half backs Knoyle and Bentley would be crucial.
However, Bentley only lasted for three minutes in the second half. The target of a number of late shots in the first half, the fly half picked up a further knock and was replaced by Lloyd Evans.
It was still an arm wrestle up front, but a triple substitution saw Dan George, Dan Murphy and Sione Kalamafoni join the fray.
But it was a moment of flair in the backs that gave Gloucester the lead on 56 minutes. Billy Burns took the ball at fly half, spun free of a tackle, put his head down and just made the line. He added the conversion for 7-5.
Burns was finding some nice touchfingers to keep Gloucester moving forward, and it was against the run of play that the hosts moved downfield and Josh Lewis restored the lead with a penalty.
Burns had an immediate chance to regain the lead for Gloucester, but his penalty dipped agonisingly under the crossbar.
With the final ten minutes looming, the game opened up as both teams strove to get the vital next score, but handling was still nigh on impossible with the ball like a bar of soap.
It went to the wire. Gloucester were still bravely running the ball from deep in an effort to overturn the one point deficit, when they were turned over on their own 10 metre line and Aaron Warren sprinted home gleefully to clinch the win for the Scarlets.
|Scarlets Score Card|
|Gloucester Rugby Score Card|