Elton John Stops Concert Due to Walking Pneumonia

Elton John struggled to power through his performance Saturday night, but eventually, he was forced to throw in the towel due to a bad case of walking pneumonia.

Sir Elton performed in Auckland and made it clear to the crowd ... he was hurting. Nevertheless, he performed until he couldn't. He had already performed for about 1.5 hours.

Check out the video ... Elton sounds really good as he performs "Tiny Dancer," but eventually he just couldn't continue. The crowd was with him all the way, giving him a standing O as he left the stage ... clearly upset.

Elton later apologized, "I was diagnosed with walking pneumonia earlier today, but I was determined to give you the best show humanly possible. I played and sang my heart out, until my voice could sing no more. I'm disappointed, deeply upset and sorry. I gave it all I had."