"I took full advantage of that," he said. "I hit a great iron shot there and made a really good putt from 12 feet for eagle."
The seasoned New Zealand representative made another birdie on the last hole before making the turn but everything changed as he headed onto the back nine.
"As soon as we made the turn, we were under the pump. We were under a lot of pressure to make up time (for slow play). I had to run five holes on the back nine, which was a new experience. It was hard to keep the momentum."
While the New Zealand men were happy with their progress, they walked off their final hole a bit deflated. At one stage the Kiwis were flying, with Koh five-under and Munn three-under.
The team had climbed all the way into a share of 12th place with the eight-under total but they got the speed wobbles on the way home, as Koh dropped two shots in his final three holes while Munn bogeyed his penultimate hole.
A total of 67 teams are entered in the 29th teams championship. New Zealand have won the Eisenhower Trophy once, when the team of Phil Tataurangi, Michael Campbell, Stephen Scahill and Grant Moorhead were victorious in Canada in 1992.