"I hit a really good drive and then obviously with the pin being tucked on the right, nice to have a short club in and hit a good committed 50-degree and I hit it perfect," Ko explained.
"Nice to make an eagle and to do that on the last makes my life easier to finish this round. Lunch is going to taste great, more so after that one."
Despite the strong finish, Ko felt like her round could have been better as she chases a second win in three weeks.
"I played really solid on my front nine and on the back I made some really clumsy mistakes. Overall I putted really well and holed some really good birdie putts and holed some good par and bogey putts, as well. Nice to finish off with a two on the last."
The Singapore heat also played a factor, and will continue to be an obstacle in the final round tomorrow.
"I thought I was fine - I had my ice bag and umbrella with me and then those last few holes, I think when the wind kind of died down, the heat really got to me. So I was like, 'I need to get into the clubhouse as quickly as possible'."
The eagle helped that quest – and her quest for another title.