The Ospreys were on the verge of victory despite George North's early red card, but Ashton Hewitt's try salvaged a draw for the Dragons.
Leinster picked up where they left off in the Pro14 as they held off Munster in a thrilling contest in Dublin on Saturday.
Harlequins were unable to recover from a dominant first-half display by rivals Saracens at Allianz Park.
There were comebacks for leaders Exeter Chiefs and Wasps in Friday's Premiership action.
Tommaso Boni and Jimmy Tuivaiti scored tries as Zebre got the better of Benetton Treviso as the Pro14 returned.
James O'Connor scored a try and kicked 17 points as the Reds achieved a record win over Western Force on Friday.
Just a couple of weeks before the Pro14 season starts, Stade Francais have been forced to cancel a friendly with Toulon.
Free agent Malcolm Marx has joined Kubota Spears a few months after opting out of his contract with the Lions.
Jack Clifford is "absolutely gutted" to have to end his career at the age of 27 after failing to recover from a shoulder injury.
An impressive showing from Wasps saw them claim a bonus-point win over Northampton Saints at Franklin's Gardens on Sunday.
Leaders Exeter Chiefs resumed the season with a win over Leicester Tigers, while Bristol left it late to down Saracens.
John Barclay has confirmed his 16-year professional career has come to an end after leaving Pro14 side Edinburgh.
The Reds came from behind to claim a bonus-point victory against a wasteful Rebels in Saturday's Super Rugby AU clash.
The final game of the season saw the Highlanders trump the Hurricanes in Dunedin on Saturday.
Marcus Smith caught the eye and mid-table Harlequins scored a narrow win over Sale Sharks as top-flight rugby union resumed in England.
The Waratahs secured back-to-back Super Rugby wins for the first time in almost a year and a half on the Gold Coast.