It has been a bad day for Irish sides in European competition today, after losses for both Ulster and Connacht.
Ulster suffered a second defeat in Pool 3 of the Champions Cup
Tries from Bryan Habana and Delon Armitage helped Toulon to a 23-13 win at Kingspan Stadium.
Craig Gilroy burst through a gap in the Toulon lines to touch down and set up an easy conversion for Jackson, but it proved to be merely a consolation try for the Ulstermen.
Ian Humphreys had a kick in the last second to try and grab a bonus point, but it drifted right and wide.
The other game in Pool 3 kicks off at 7.45 and sees Scarlets host Leicester.
Leinster take on Castres Olympique at Stade Pierre-Antoine tomorrow in Pool 2.
Meanwhile, Connacht conceded five tries in a 33-13 defeat away to Exeter Chiefs in Pool 2 of the Challenge Cup.
It was Will Chudley, Gareth Steenson, Damien Walsh, Dave Ewers and Ben White with the Chiefs' tries.
Craig Ronaldson, meanwhile, kicked a pair of penalties for Pat Lam's side, while Fionn Carr nicked a try for Connacht on the occasion of his 100th Connacht cap.
