Wales’ leading cap-holder was afforded a standing ovation when he was replaced during the second half before the Scarlets produced a late fight-back.
Gareth Davies scored twice before Liam Williams and a penalty try wrapped up a thoroughly entertaining victory at an emotional Parc Y Scarlets.
However the rousing win was not enough to clinch a place in the RaboDirect Pro12 play-offs.
Cardiff Blues twice threatened to spoil the party as Andries Pretorius, Alex Cuthbert and Harry Robinson all scored in a thrilling derby.
It was a fitting finale for Jones who brought down the curtain on a 15-year association with the club where he started his career.
Since making his debut as an 18-year-old, Jones has become a modern-day talisman for both club and more recently region.
A local lad, born in Carmarthen, few have worn the famous scarlet jersey with such distinction as Jones and none have scored more points.
Jones surpassed Andy Hill and Phil Bennett last year as the club’s leading points scorer, amassing a remarkable 2850 points in 315 appearances.
Bennett was among the member of the 1972 team that defeated the All Blacks who were introduced to the crowd before kick-off.
Yet it was Cardiff who stunned Parc Y Scarlets with a score inside two minutes.
Casey Laulala and Chris Czekaj made the most of a turnover to hand Pretorius a straight-forward 30-metre canter to the line.
Priestland responded with a penalty though teenager Robinson went close to extending the Blues lead, only to be denied on the line by Dominic Day and Sean Lamont.
It was a telling intervention and within minutes the Scarlets completed a 14-point swing when Davies scampered over with an opportunist solo try from 50 metres out.
Priestland’s conversion handed the Scarlets a 10-7 lead at the end of a thoroughly entertaining first half.
Blues kicked off the second half as they did the first with an early try. Dafydd Hewitt made the early yards before Laulala and Czekaj combined again, this time for Cuthbert to score three minutes in.
The Scarlets proved they could match the Blues’ handling skills when Davies finished a sweeping move for his second.
But Cardiff hit back again within three minutes as Robinson touched down after breaks by Pretorius and Scott Andrews.
Parks missed the conversion but nudged Cardiff 20-17 ahead on 63 minutes, however Parc Y Scarlets came to its feet in the 66th minute when Stephen Jones was replaced.
Without their talisman, Scarlets still conjured a third try when Liam Williams shrugged off two defenders to edge 22-20 ahead before a penalty try five minutes from time, following a collapsed scrum, wrapped up a thrilling victory.
