The Ospreys followed up their 34-17 win over Munster with a surprise away win over the reigning Champions, Llanelli Scarlets, at Stradey Park. Wales international Gavin Henson was the scourge of the Scarlets in a comfortable 23-6 win.
The win leaves the Ospreys on 9 points, two clear of Connacht, who so narrowly missed out on joining them nine, courtesy of Paul Burke's last-gasp penalty.
Leinster's fine 26-15 win away to Ulster earns them third place, on points difference ahead of Cardiff Blues. The Blues added an 18-8 home win against the Gwent Dragons, thanks to two charge-down tries, to their away draw with Leinster last week to join Leinster on 6 points.
Ulster are joined on 4 points by Glasgow, who had a narrow 10-7 win away to The Borders in poor conditions.
Munster, on three points, are two clear of Edinburgh and The Borders, while The Dragons are pointless at the bottom of the table, though they, along with Edinburgh, have only played one match.
See the tables section for league table