One year after becoming the youngest player ever to win an LPGA Tour event, Lydia Ko once again made history at the CN Canadian Women’s Open on Sunday.

The 16-year-old amateur from New Zealand became the first amateur to win two LPGA events and the first amateur to successfully defend her title after shooting a final-round 65 to capture a five-shot victory at Royal Mayfair Golf Club in Edmonton.

“I`m pretty surprised, but I played some really good golf out there, so I was really happy about that,” said Ko. “My goal today was to shoot 5 under and just play my own game. If somebody else shot better, then I can`t do anything about it.”

Sitting one shot back of third-round leader Caroline Hedwall entering Sunday’s final round, Ko got off to a hot start and never looked back. She birdied five of her first eight holes of the day and stormed out to a big lead.

The first blip in Ko’s scorecard came on the par-4 13th when she missed her par putt and settled for her only bogey of the day. She capped off the round with a 15-foot birdie putt on the 18th hole and gave a shocked reaction once she received a raucous cheer from the Canadian crowd.

“I didn`t have it coming,” said Ko of her final putt. “That`s why I was like oh, my God. I was pretty worried it would just go straight down because I knew it was a slippery putt. No, I just hit a little bit, and it trickled down in the hole.”

Ko’s 64 was three shots better than the next best round of the day, which was shot by runner-up Karine Icher. The France native finished second, but thanks to Ko’s amateur status, Icher took home the $300,000 first-place prize check.

“Yeah, no, not too bad for me, obviously,” said Icher. “But I would love to win one one day, but it`s nice for her. She deserves it. I`m sure she`s a hard worker, and especially in Canada for her it`s special.”

In addition to Icher, there were a number of other players chasing Ko who had taken part in last week’s Solheim Cup. Fellow European Solheim Cup Team members Suzann Pettersen and Caroline Hedwall were paired in the final group with the 16-year-old Ko.

Pettersen was making a push early before faltering late, picking up two bogeys and a double bogey in her last five holes. The Norwegian finished in a tie for seventh at 7-under-par.

Hedwall followed up her historic performance at the Solheim Cup last week with a tie for third finish. She became the first player to go 5-0 in Solheim Cup competition and tied her career-best LPGA finish this week (2013 Kraft Nabisco Championship).

“This is one of my better finishes on the LPGA, so I`m very happy this week,” said Hedwall. “I`m still waiting for my first win, but hopefully it will come soon. I slept okay, to be honest. I was just excited to come out and play today. I had a lot of fun out there. It`s just that Lydia was way too good today.”

Ko has played in a total of 14 LPGA events over the past two seasons and has yet to miss a cut. Her worst finish over that stretch was a tie for 42nd at the RICOH Women’s British Open this month. The New Zealand resident has now recorded two wins, four additional top-10’s and four additional top 20’s.

The victory marks Ko’s fourth professional win. Along with her title at the 2012 CN Canadian Women’s Open, Ko also won the 2012 Women’s New South Wales Open on the ALPG and the 2013 ISPS Handa Women’s New Zealand Open on the Ladies European Tour.

Ko became the first player to defend a title on the LPGA Tour since Yani Tseng who won back-to-back RICOH Women’s British Opens in 2010 and 2011.

“When I saw that record, I thought wow, that is amazing,” said Ko. “Who can do that? And to have done that myself, that`s pretty special. Last year was a three shot lead through or two, two shot lead, so I was pretty happy about that. Now having five shots, it makes it even better.”

Ko was 15 years, 4 months and 2 days when she won the 2012 CN Canadian Women’s Open at Vancouver Golf Club. And the youngster now also sits second on the list of youngest winners in LPGA Tour history.

• Lydia Ko, 2012 CN Canadian Women’s Open (72-hole event) at 15 years, 4 months, 2 days *
• Lydia Ko, 2013 CN Canadian Women’s Open (72-hole event) at 16 years, 4 months, 1 day *
• Lexi Thompson, 2011 Navistar LPGA Classic (72-hole event) at 16 years, 7 months, 8 days
• Marlene Hagge, 1952 Sarasota Open (18-hole event) at 18 years, 14 days
• Marlene Hagge, 1952 Bakersfield Open (18-hole event) at 18 years, 2 months, 15 days
* not a member of the LPGA