Rory McIlroy sensationally accused Bryson DeChambeau of holding The Open hostage for waiting late into the night to decide whether he would pull out in protest over his two-shot penalty.

A furious DeChambeau had threatened not to play his third round at Royal Birkdale during animated remonstrations with officials over whether he had improved his lie on the fifth by stomping down some long grass around his ball.

DeChambeau's agent Brett Falkoff had later refused to rule out a shock withdrawal as the two-time Major winner hit balls on the driving range in pitch darkness, telling reporters: 'Let's see if he shows up late tomorrow afternoon, your guess is as good as mine.'

It meant the rest of the field did not learn of their official tee times until around 11pm, which Englishman Marco Penge described as 'a joke', with DeChambeau only posting on social media after midnight to confirm he was playing.

'Late night for everyone,' said McIlroy. 'I won't pretend to be up here and defend Bryson. I'm not particularly fond of him. I think a lot of it's performative. I think a lot of it's for attention.

'To hold the tournament hostage like that, and to have all of us, players, volunteers, everyone waiting on him to depart, I didn't feel like it was a great look.'

McIlroy, who finished his third round at two-under par heading into the final day, said the decision to hand DeChambeau a two-shot penalty was the correct one.

'I was watching it live,' he added. 'I was up in the players lounge watching it with a few other players, and as soon as he made the step into the ball, we all sort of looked at each other, and we were, like, that didn't seem right.

'Then when I heard that he was called in by the rules officials, I think we all - it was pretty obvious for why.

'I think there's no doubt that he improved the line of his backswing. Again, it's like, whether it was careless or whether it was intentional, I don't think it matters. Hopefully it was careless, but I think the two-shot penalty was justified for sure.'

When Daily Mail Sport asked McIlroy if he thought DeChambeau knew what he was doing, the Northern Irishman replied: 'I'm not in his mind - but it didn't look good.'

McIlroy finished up his third round at two-under-par for the tournament, with a one-under 69 leaving him seven shots off the lead.

DeChambeau, meanwhile, dropped to five-under with his penalty but is still within reach of the leaders as his third round begins on Saturday afternoon. 

The fallout from the DeChambeau controversy threatens to rumble on, however, with world number one Scottie Scheffler struggling to remain tight-lipped on the incident after his level-par round left him at four-under heading into the final day.

'I don't really have a ton to say on it,' said Scheffler. 'Actually, I do have a ton to say. I haven't decided exactly what I want to say publicly yet. I do have some thoughts. 

'I just...I don't really feel like now is the time or place for me to comment. We're in the middle of a tournament, and I'm focused on what I need to do. 

'Like I said, I have a decent amount of thoughts, but probably nothing that I'm concerned with right now. I just feel like it's not a road I want to go down today.'

DeChambeau received huge cheers on the first tee at Birkdale but also faced pockets abuse from spectators, with some calling him a 'cheat' and others light-heartedly warning him not to stand too hard on the grass in the rough.

While McIlroy made it clear what he thought of DeChambeau, and Scheffler merely hinted at it, the YouTube star did receive some words of support from fellow countryman Max Homa.

'I've known Bryson for a very long time, and he's an interesting human at times, but I know he would never cheat the game of golf,' said Homa. 'I don't really love how it happened. 

'It's not that the R&A said that he did it intentionally, but that rule as a professional golfer feels like it's written inherently to protect against people trying to improve their lie. 

'So I just hope that doesn't create a narrative because I don't believe that of him.'