Marti Cifuentes saw his much-changed QPR side take the lead when Hatters goalkeeper Thomas Kaminski diverted Elijah Dixon-Bonner’s shot into the path of Brazilian right-back Santos, who converted on his senior debut after joining the club in July.

Luton equalised in sensational fashion when Nelson’s shot from a tight angle outside the box following a corner raced into the far corner of the net.

Visiting manager Rob Edwards, whose players began the season on a four-game winless streak, brought five new faces into the team from Town’s 1-0 loss at Preston North End in the Championship on Saturday, including midfielder Marvelous Nakamba in the starting line-up for the first time since December.

Edwards made three substitutes at half-time, bringing on Nakamba, Reece Burke and Amari’i Bell for Mads Andersen, Tom Holmes and Liam Walsh, while QPR brought on Jake Salter-Clarke for Steve Cook in defence.

Luton’s Morris, whose shot had given Nelson a chance, was parried with a header by Walsh before Adebayo’s shot deflected after Walsh failed to hold onto Chong’s effort.

Kaminski also had to intervene and parried Alfie Lloyd’s shot and Zan Celar’s header from a Karamoko Dembele free kick, so that the game ended 1-1 after 90 minutes and went to penalties.