Complex sentence: The Scarlets won five of their six matches, losing only to Agen, and finished at the top of their pool before losing to French club Biarritz 27--10 in the quarter-final.
Split into simpler sentences: The Scarlets won five of their six matches, losing only to Agen, and finished at the top of their pool. Nonetheless, they were defeated by French club Biarritz Olympique 27--10 in the quarter-final.