Crowther, 13, is in Europe competing with some of the best players in his age group.
"It has happened very quickly for him with big changes over the last year, year and a half.
"He is a very dedicated player. He just reached the final in doubles in a tournament in Copenhagen in Denmark."
Luna came up with a unique method to prepare Crowther for playing on clay courts in Europe.
"You have no idea how hard we have to work because we don't have clay courts here.
"So we went to Memorial Park and I put some thick socks over the wood just to get him used to running and sliding then I would throw balls so he could get used to it.
"That was the best way to do it.
"I was a bit concerned for him that first match in Europe because it is so difficult if you have never played on clay.
"But the very first match he won so that was really, really exciting."
Luna has seen tennis grow in the junior age groups in the six years he has been working at Tauranga Lawn since arriving from Mexico.
"I have been getting a lot of support from the club's presidents which makes a lot of difference when the committee is behind you and pretty much approve your programmes,' he said.
"This year was the second year I have gone to the coaches' conference at the Australian Open and the club helps with that which is very motivational for me to try and get better and better.
"The other thing is being surrounded by good coaches in the area.
"Peter Blow has made a big impact. We work together to pull the standard of the game up and we coach the Western Bay junior squads together."
