By March she rose to the #3 women's world amateur ranking. At this point, her rivalry with good friend Cecilia Cho heated up. Ko claimed the Australian Stroke Play title by beating Cho in a two hole playoff, but lost the Australian Amateur Match Play in the quarterfinals.

Ko then won the New Zealand Stroke Play Championship, beating Cho by 9 shots. This event set up the draw for the New Zealand Match Play Championship, which once again ended up being a final matchup between Cho and Ko. And once again, Ko triumphed, beating her friend 4 and 3 in the final despite the fact Cho had won the event the two previous years. This allowed Ko to rise to #1 in the amateur rankings, knocking Cho down to #2. Ko became the first woman to ever hold both the Australian and New Zealand Stroke Play titles in the same year.

In May, Ko also won the Muriwai Ladies Open, beating a field of pros and amateurs. She then launched her first effort to play in the big European and American amateur events. She lost early in the British Women's Amateur, but claimed the co-medalist honors at the US Women's Amateur before falling in the second round of match play.

Ko then had an operation to fix an ailing wrist, and missed six weeks of action while she recovered. But in early 2012, it did not take her long to get back to her winning ways. In January, she won the Australian Women's (Match Play) Amateur. She is believed to be the first woman to EVER hold the Australian Women's Match Play + Stroke Play titles and the New Zealand Amateur Stroke play and Match Play titles all at the same time. That's an extraordinary accomplishment for anyone, let alone a 14 year old.

And yet, Ko was just getting warmed up. The next week, she attended the NSW Open on the ALPG. The previous year she had come within one stroke of rewriting the record books when she finished second here. This time, she left nothing to chance. In the second round, she shot a blistering 64 to take a four shot lead. In the final round, despite strenuous pressure from professional Lindsey Wright, Ko never wavered, and won the tournament easily by four. She thus became the youngest person to ever win a professional golf event, anywhere in the world, breaking the record held by Ryo Ishikawa of Japan, who was 15 when he won his first pro title. She also crushed the women's record held by Amy Yang, who had won the ANZ Ladies Masters as a 16 year old in 2006.

There had been only a couple of press people covering the win, but as news of her achievement got out, Ko was swamped with media attention. As it turned out, she was playing the very next week at the RACV Australian Ladies Masters, as was another teen superstar in the making, Alexis Thompson. Ko had never met Thompson before, and the promoters wasted no time in pairing the two for the first two rounds of the Masters. Ko's goal was to simply make the cut, but she wound up in the top 20 most of the week before fading a bit on Sunday to finish tied for 32nd. A week later, she managed an 18th at the ISPS Handa Australian Women's Open, her first ever LPGA event. She was also the low amateur at this event. It was a foreshadowing of what was to come.

Lydia Ko's summer of 2012 ranks as one of the most amazing stretches of golf anyone has ever played. Simply put, she put one remarkable performance after another together, culminating in a record shattering appearance at the Women's Canadian Open in August.

The fun started when she traveled to the States to play in her first Major, the US Women's Open. She had qualified for the event by being the top amateur in the world, and for much of the week, she was easily the top amateur in the field. She struggled mightily on her final three holes and almost gave the low amateur crown away, but she still held on, finishing tied for 39th.

Next she played at the US Girls Junior Championship. She made it all the way to the semifinals, where she lost to American Alison Lee. A few weeks after that she played at the US Women's Amateur, arguably the most important amateur event in the women's game. Lydia finished runner-up in the stroke play portion (Hyo Joo Kim won that, but lost in the second round of Match Play). In Match play, she worked her way through the field, meeting the second ranked amateur in the world, Ariya Jutanugarn, in an epic semifinal clash. Ko downed the Thai teen, then beat American Jaye Marie Green in the final 2 and 1. Ko became the second youngest in history, behind Korean American Kimberly Kim, to ever win this title. And amazingly, she had an even bigger coup in store after that!

Two weeks after the Amateur win, Ko was in the field at the LPGA's CN Canadian Women's Open in Vancouver, British Columbia. Ko played well the first two days, hung tough through some dicey play on Saturday, and found herself in the lead with 18 holes to go. On Sunday, playing with Major winners Jiyai Shin and Stacey Lewis, Ko dug deep, but still was caught by the turn. It was at that point that she kicked into another gear, producing one of the most dazzling displays of golfing excellence in LPGA history. She put the hammer down, making four straight birdies to blow past the field of Major winners and grab the historic three shot win. She was the youngest player (by more than a year) to ever win an LPGA event at just a little over fifteen years of age, shattering the record by Lexi Thompson that had been set just the previous year. She also became the first amateur in over forty years to win on the LPGA tour, and just the fifth in history. The last amateur who won, Joanne Carner, was nearly twice Ko's age when she did it. And Ko beat a field containing almost all the best women's golfers in the world. It was an insanely brilliant performance that catapulted the teenager into the mainstream press. Golf Channel, not known for in depth LPGA coverage, devoted the first 20 minutes of their Golf Central show to Ko's triumph before they got to the PGA tour results.

The next month, Lydia played at her second LPGA Major, the Ricoh Women's British Open. In the terrible weather at Hoylake, Ko once again earned low amateur status, finishing tied for 17th. She next showed up at the Women's World Amateur Team Championship, also known as the Esprito Santo Cup, representing New Zealand. Although Korea (headed by Hyo Joo Kim) won the team trophy, Ko won the individual honors, dusting the rest of the field by six strokes.

Ko played in the Swinging Skirts event in Taiwan at the end of the year. She finished tied for 26th. After Christmas break, she returned to action at the Australian Women's Amateur, where she was defending champion. But she bowed out early in match play, and the event was won by Korean Australian star Minjee Lee (who had won the US Girls Junior in 2012). The next week, she was back to defend another title at the New South Wales Open. She gave it a great effort, and found herself in a duel at the end with 2011 champion Caroline Hedwall and Minjee Lee. Ko made a masterful par save on the 16th hole on Sunday, but made a fatal mistake off the tee on 17, and Hedwall won the event with Ko finishing second and Lee third.

Ko didn't have to wait long for another shot at a pro trophy. Just two weeks later she was back in action at the New Zealand Women's Open. She had come close to winning this event several times, but neither she nor any New Zealander had ever taken the title. But in 2013, Ko started well, finishing the first round within a shot of the lead. She had a share of the round 2 lead with Korean Seon Woo Bae, who shot a course record 64 just to catch her. In the final round, Ko was severely challenged by several players, losing the lead several times, but she hung tough, sinking a par on the final hole for a one shot victory. This was her third pro win in a little more than a year, and she was still not even 16 years old. Simply incredible! She also became the youngest winner in the history of the Ladies European Tour, beating the record once held by Korean Amy Yang.