But his departure was announced after the game in Llanelli.
Delaney had been due to move from head coach to director of rugby at the Scarlets next season with former Wales and British & Irish Lions scrum-half Dwayne Peel arriving from Ulster.
Peel – who had initially agreed to join Cardiff Blues – will now be the main man in charge as Scarlets look to improve on a poor season next term.
Delaney said: “Today I announce I will be leaving the Scarlets. It has been a great pleasure to coach this fantastic club.
“It has been the most difficult of seasons with the global pandemic creating many challenging issues the staff and team here have dealt with incredibly well.
“I leave with great memories of two wonderful years out west.
“We have enjoyed some great times, which in the first year we were able to share with the supporters being there.
“I won’t forget the European games away to Toulon, Bayonne and London Irish where the travelling support was simply unbelievable.
“Our Champions Cup match against Bath this season was one I know the travelling faithful would have loved.
“I know the club is in great hands moving forward into the new season and I wish it nothing but the best.
“I want to say a huge thank you to the great staff and the outstanding playing group here at the Scarlets and of course the supporters. I’ve loved every day working with you all.”
Delaney joined the Scarlets as defence coach ahead of the 2019-20 season, taking over as head coach from Brad Mooar for the 2020-21 campaign.
Dai Flanagan will take charge of the side as interim head coach for the remainder of the Rainbow Cup campaign.
Scarlets executive chairman Simon Muderack said: “We would like to thank Glenn for his wholehearted commitment to the Scarlets during his time here and wish him well for the future.”
