Actor Idris Elba went to the aid of a woman who collapsed as she watched a performance of his new play Tree.
The show was briefly halted while the Luther star made sure the audience member was seen by paramedics.
The play continued and the woman was now "fine" said bosses of Manchester International Festival (MIF), which is hosting a two-week run of Tree.
Most of the audience stands throughout the 90-minute performance, described as a mix of drama, music and dance.
The woman collapsed during a performance of Tree at Upper Campfield Market Hall in Manchester on Wednesday.
MIF's artistic director John McGrath said: "She was right next to Idris in the audience so he was there trying to help out and make sure that paramedic support workers got to her.
"I believe that the lady is now well and fine but it was certainly helpful that Idris was there to help out with that."
The play is at the centre of a row after after two writers who worked on it claimed they were shut out and suffered "intimidation and disrespect".
Tori Allen-Martin and Sarah Henley said they worked on it for four years but were "pushed off" and got no credit for the play, which is presented as the work of Elba and Kwame Kwei-Armah.
Elba posted a statement on Twitter on Thursday saying the writers had decided to leave the project when when "new ambitions" were proposed.
He stated that they had been acknowledged in the foreword of the play's programme.
Representatives of Elba said they would not comment on Wednesday's incident.
A spokesman for MIF said seating was available at the play for those who needed it.