Leigh coach Kieron Purtill said he had "no complaints with the decision" after Peter Mata'utia was sent off during the 52-22 Challenge Cup quarter-final defeat to Leeds.
Centurions full-back Mata'utia made a dangerous lift on Rhinos hooker Matt Parcell in the 10th minute and was given his marching orders by referee Chris Kendall before winger Matty Dawson followed suit for dissent in the closing stages.
Leigh had struck first through prop Nathan Mason's close-range score but Brian McDermott's side took control after Mata'utia's sending off and led 40-12 at the break.
They ran in a total of nine tries to seal their place at the Macron Stadium in Bolton for the Challenge Cup semi-finals on August 5 as part of a historic double-header.
On the decision which resulted in Mata'utia being shown red, Purtill said: "Peter's sending off had a big effect on the game but I've no complaints with the decision.
"Peter has been fantastic for us all season and he hasn't got a nasty bone in him. He goes out to play the game how rugby league should be played and he doesn't need me to say it was the wrong thing to do.
"He's upset in there because he knows he's let himself and the group down. We have to rally round him now."
Leeds had beaten Leigh at this stage of the competition in 2012 and 2014 but this latest meeting was switched to the home of Featherstone Rovers because of the Test match cricket taking place at Headingley.
McDermott was left with three injury concerns as Parcell was forced off midway through the first half with concussion while Carl Ablett and Jimmy Keinhorst also departed during the opening period.
The Rhinos coach revealed: "Parcell should be okay for next week but we think Ablett and Keinhorst have calf and hamstring tears respectively.
"I didn't think Leigh played grubby. Derek Beaumont [Leigh's owner] has just accosted me out there and reminded me they're not that sort of team and I agree. Credit to them.
"It was a tough, solid performance from us and of course the early sending off would have affected Leigh. The dynamic changed dramatically, it made it an easier day for us. It was a sending off but I don't think he meant to do it."
Leigh ran in a total of four tries through Mason, Drew Hutchison, Ben Crooks and Liam Hood but Purtill admitted his concern at their lack of discipline.
Centurions prop Jamie Acton and Leeds forward Brett Ferres were sinbinned during the second half and Purtill said of his side's indiscipline: "It could be costly.
"A lot of frustration came out at the end because of the decisions and with how we played in the second half.
"It's something we've worked really hard on as a group in the past few weeks and we've been pretty good in that area. In the big games coming up, we need to keep our composure."