Before that, Gloucester had a penalty on halfway and put up a contestable kick, which held up in the wind and bounced back towards them.
Munster's Craig Casey was alive to it and set off on a counter attack. Casey and Mike Haley could not quite get the job done, but Gloucester stopped them illegally near the tryline and Caio James was sent to the sin bin.
Earlier, there were contrasting fortunes for English Prem clubs in the Champions Cup.
Sale scored five tries in an impressive 35-14 victory at Clermont Auvergne, while Saracens had to settle for a losing bonus point from their trip to Durban.
Half-time: Bordeaux Begles 31-14 Scarletspublished at 18:21 GMT 13 December 2025
18:21 GMT 13 December 2025
Meanwhile, it has been breathless stuff at Stade Chaban-Delmas.
Scarlets took a surprise early lead, but after that the European juggernaut has been in full flow, with France fly-half Matthieu Jalibert in sensational form.
They have five tries in the bag already, but Scarlets have refused to lay down with two of their own.
The teams head down the tunnel for a well-earned break.
Half-time: Munster 7-3 Gloucesterpublished at 18:20 GMT 13 December 2025
18:20 GMT 13 December 2025
The home fans raise the decibel level as Munster threaten the Gloucester line with the clock in the red.
Gloucester's defence holds firm and the whistle blows for the interval.
Dan Kelly's converted try for Munster has the home side in front at half-time against Gloucester, who nudged in front early on with George Barton's long-range penalty.
Converted try: Bordeaux Begles 31-14 Scarletspublished at 18:18 GMT 13 December 2025
18:18 GMT 13 December 2025
Tiaan Jacobs (con: Jalibert)
It's more magic from Matthieu Jalibert, a quick one-two before offloading to the giant South African Tiaan Jacobs, who rides the tackle before stretching for the line.
It's a killer blow for Scarlets, who concede a fifth try just before half-time.
Jack Crowley's penalty attempt from about 35 metres only just reaches the posts, showing the strength of the wind that Munster are playing into in this first half.
The kick also goes wide so Munster's lead remains at four points.