Connacht were leading 10-3 at half-time in Llanelli, only for Shingler to score a penalty at the last and send Scarlets clear at the top of the table.
In contrast Connacht slipped to fourth, and will be looking to exact a measure of revenge this weekend - and rectify a four-game GUINNESS PRO12 losing streak in the process.
Cardiff Blues and Edinburgh are two of the most in-form teams in the league at the moment, though something will have to give at BT Sport Cardiff Arms Park on Saturday evening.
The Blues look to be on course for a revival under Danny Wilson having won three league games on the spin, while third-place Edinburgh can boast the same record.
But the weekend is due to kick off with a bang on Friday night as Newport Gwent Dragons host a Leinster side that powered to an impressive win at Ospreys last time out in the GUINNESS PRO12.
Indeed stopping Leinster will take some doing - the Irish province haven't lost in the league since October 16 - but the return of Wales international Hallam Amos is a huge boost for the Dragons.
On Sunday, Glasgow Warriors travel to Ospreys with their tails up after ending their four-game losing run in all competitions by beating French powerhouses Racing 92 last weekend.
However, despite their setback against Leinster, Ospreys are slowly but surely creeping up the GUINNESS PRO12 table - they've won five of their last six on domestic duty.
It ended 30-19 in the Warriors' favour back in November - expect another open game.
Zebre are likely to be tough opposition for Munster this weekend after capping of their campaign in Europe by winning three games in the competition for the first time in their history.
And they will have to overcome another big hurdle here - Munster have won their last nine games against Italian competition.
Last but not least, Ulster also go to Italy to take on a Benetton Treviso side still seeking their first win this season.
Ulster, sixth in the table, are a wounded animal after a bonus-point victory against Oyonnax was not quite enough to see them through to Champions Cup quarter-finals.
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