The 20-year-old brake service engineer died after being injured in a trail bike accident on the outskirts of the town last weekend.
Between 600 and 700 people farewelled Mr McKenzie, who was described as a quiet, thoughtful and unassuming young man, dedicated to his work and to his service as a volunteer fireman.
About 60 firefighters, police and St John volunteers from throughout Central Otago formed a guard of honour at the end of the service.
In his tribute, Alexandra's Chief Fire Officer Russell Anderson said the youth of today too often made the headlines for the wrong reasons, but Mr McKenzie was a role model for all generations - young and old.
"If they had a fraction of Phil's qualities, they would be better people."
He was a loyal, dedicated young man and a valuable part of the fire service family, Mr Anderson said.
Although only 20, he had qualified as a senior firefighter and was about to receive a certificate marking his three years of service as a fireman.
In that time, he had attended 384 calls.
A trio of young firefighters - Mr McKenzie, Charlene Ruffell and Kym Pollock - were the "three musketeers" of the Alexandra brigade and there was good-natured competition between the three friends, Mr Anderson said.
Miss Pollock said Mr McKenzie's generosity and trust made him an inspiration to many people.
He was like a brother to her and she would miss his quick-witted comments and cheeky texts.
Deputy Chief Fire Officer Mark Hutton said Mr McKenzie was one of the brigade's youngest members when he joined, just before his 17th birthday.
"The community can be proud of young people like Phil who contribute so much to their community," Mr Hutton said.
Mr McKenzie had won the brigade award for most call-outs and musters for two successive years and was about to receive it for the third year in a row, he said.
He was proud to count Mr McKenzie as a friend as well as a colleague and said the young man, who always had a smile on his face, had packed a lot into a short but full life.
Jamie Moran employed him as an apprentice brake service engineer.
"He got stuck in and showed a maturity way beyond his years and his attitude was an inspiration to us all. The standard of his work was the same as everything in his life - as high as you could ask."
Diane McKenzie said her son had achieved so much in a short time and his family was grateful for the wonderful times they had shared.
The young man was passionate about his cars, and the vehicle he had been restoring, a green Toyota Corolla, was brought to the service on a trailer.
Mr McKenzie's casket was painted the same colour as his car and sported a chrome exhaust pipe as well as a personalised number plate:"Phil".
One of the Alexandra fire engines was used to carry his casket to the cemetery, travelling past the Alexandra Fire Station and his workplace on the way.
The fire siren was sounded as a mark of respect.
