"When she went in for her final weigh in the girl she was fighting was about 2 foot taller than her. We were like holy heck."
Warren said he was warned by the Australian coach that Summer's opponent who was from New Caledonia had beaten their fighter in a previous bout.
"He told me she was a really tough fighter and it was going to be a hard fight for Summer."
But Summer was confident after they had the official weigh-in, Warren said.
"They had to do a stand off and when Summer looked into the girl's eyes she turned away. She said 'that girl looked away from me, I think I've got this won coach'."
When it was time to fight Warren said the roar of the crowd when Summer's opponent came out made her really nervous.
"Summer was saying 'what's going on'? I just told her the crowd were cheering for her. When we went out the crowd started cheering and she was really surprised."
Summer had three, 2-minute rounds to try and impress the judges Warren said.
"Right from the start Summer looked to dominate her opponent and it worked because in the second round the girl backed off."
Although Summer was dominating the fight, Warren was still concerned about home town advantage.
"I told her she needed to knock her opponent out otherwise she may not win.
"Well she went out in the third and did everything but knock this girl out.
"Summer came back and said 'I've lost coach, I didn't knock her out'. I just told her she did enough."
There is no rest for Summer, who returned on Sunday. The youngster will take part in the New Zealand Boxing Championships being held in Hamilton tomorrow.
Rotovegas Boxing Gym has 13 fighters going to the three-day event including four-time national champion Ricaia Warren and five-time national champion David Faataape.
Warren, who is the head coach at Rotovegas Boxing Gym, said all the fighters had trained hard and he was confident they would do well.
The championships are being held at the Claudelands Arena starting on Thursday with the finals on Saturday.