As Barr cut towards the rail entering the turn he was given a firm shove into the outer lanes by Mellon, an incident which was reviewed by judges but controversially not deemed an infraction.

“He was a foot behind and came trying to dive through the gap that was closing,” said Barr. “I’m much smaller and slighter than he is and he pushed me out of the way. But that’s indoor 400 running. I probably should have kept an eye on the peripherals.”

Barr was carrying a niggle into the race and when he lost several metres after being pushed, he chose not to continue, visibly annoyed as he slowed to a stop.

“I went with my gut and said there’s no point carrying on — I was going to find it tough to get back up with the lads. I probably should have stayed a little bit wider but that’s a lesson learned. It’s a completely different ball game indoors.”

In his absence, 20-year-old Cillín Greene produced the performance of his life to seal victory in 47.19, a personal best that secures him a spot at next week’s European Indoors.

“When I saw the time, I was in shock,” said Greene. “I was running blind so didn’t know about the controversy but my plan was to get out hard. I’ve no weight on me at all so if I got a push that was my race gone.”

Mellon held off Brandon Arrey to take silver in 48.02.

There was no such drama for medal hopes Mark English or Phil Healy in their respective finals, the pair both coasting to victory. English secured his sixth indoor 800m title with a composed display, the 25-year-old seizing command on the final lap and cruising to the finish in 1:51.77, with Zak Curran second in 1:51.91.

“My plan was to get the win, first and foremost — to take the lead at 600m and hang on for dear life,” said English, although the manner of his victory suggested he was never out of second gear. “My fitness is definitely as good as it has been, if not better.”

English, the European indoor silver medallist in 2015, has been well off his best in recent years, but he revealed that a biomechanical assessment in Manchester last November has identified key areas of weakness, which he has been working on in recent months.

“It was injuries that held me back and I went to see what adjustments I had to make to my form,” he said. “I’ve worked a lot on that over the winter in the gym. It does show in terms of efficiency at top speed.”

Phil Healy stamped her authority on the women’s 400m with a powerful display of sprinting, Ireland’s fastest ever woman bolting from the blocks and coming home a wide-margin winner in 52.81 ahead of Sophie Becker (53.95).

Afterwards, she completed a session of 150-metre repetitions on the track, her sights already turned to next week’s championships in Glasgow.

She will enter the event as the fourth fastest in Europe, igniting hope of a podium finish. “Everyone can talk about medals, but the pressure is what you put on yourself,” she said. “I’ll go out there, it’ll be my race, my lane, and I’ll have two races before I can even think of a medal.”

Joseph Ojewumi earned the title of Ireland’s fastest man after taking victory in the men’s 60m in 6.78, a hair ahead of Marcus Lawler (6.79), while Molly Scott took the women’s title in 7.32.

Leon Reid and Rhasidat Adeleke claimed the 200m titles in 21.42 and 24.13 respectively, while John Travers was particularly impressive in the men’s 3000m, taking gold in 8:07.89.