The Ospreys v Scarlets Welsh derby was marred by a controversial sending off in the fifth minute.
Scarlets back rower Tomas Lezana was shown a straight red card for a high tackle on Rhys Davies that left the visitors with a monstrous mountain to climb.
Lezana failed to adjust his tackle height and made direct contact with Davies' head, resulting in the Osprey having to leave the field to be replaced by Alun Wyn Jones as he underwent a HIA.
