Wynne Gray: Oh-K and Oh, yes — Ko back to best

Lydia Ko celebrates her 21st birthday in style, winning at Lake Merced. Photo / AP

Multiple changes wrapped around Lydia Ko's life and golfing game in the last two years as theories expanded about her lack of success.

She had set such high levels in her young but stellar career that any slide in results attracted over-zealous inquisitions about her future.

She switched coaches, clubs and caddies and trimmed 8kg for the start of her 2018 LPGA season as she struggled to finish any higher than a tie for 10th at the HSBC women's world championship.

The Jutanugarn and Korda sisters claimed the highlights with Inbee Park, Shanshan Feng, Lexi Thompson and So Yeon Ryu while another Ko, Jin-Young, pushed into the limelight as she shifted the success of her game in Asia into the wider comparisons of America, Australia and Europe.

The form wavered and the victory drought increased but Ko's demeanour stayed the same. Her smile may have looked a little wan at times but it was there through the tugged tee shots and course management malfunctions. She worked hard at her game yet the reliability teased her.

That storyline was pay-dirt for golf's analysts and commentators who marvelled at Ko's ascension to No1 on the LPGA tour for 85 successive weeks and were now uncertain whether she would rediscover those standards.

Ko teased the victory dais last year with three runner-up finishes but the gap between triumphs pushed out to 43 events since July 2016.

In a week when commentator and former world champion Dennis Taylor suggested snooker was a touch ahead of golf as the toughest sport to play, Ko turned 21 and made her move at the Mediheal Championship at Lake Merced near San Francisco.

Among a slew of top shots, two stood out.

Her pitch from a tight lie on the 72nd hole was exquisite. It feathered the edge of the cup to leave Ko with a tap-in birdie and send her into a playoff with Minjee Lee, another of the young brigade with Korean links.

The pair played the par five final hole again and this time Ko's 240 yard fairway metal had eyes for the pin.

As she slowly retrieved her victorious short eagle putt from the cup, Ko's emotions engulfed her.

Tears overlaid Ko's quivering smile as her playing partner Jessica Korda then other tour players congratulated her. Ko's belief may not have shifted during her winning lull but that interlude had been awkward.

New coach Ted Oh deflected any credit towards Ko who had worked relentlessly and methodically through her issues to the winner's rostrum and in her victory speech Ko emphasised more work was needed. She had come up with one answer but wanted more.

Celebrations meant pizzas and a trip to the bowling alley for Ko and her close friends and another reward for golfing fans in New Zealand and around the globe who have delighted in her success.