Philadelphia, PA (SportsNetwork.com) - James Hahn birdied the second and third playoff holes to defeat Paul Casey and Dustin Johnson and win the Northern Trust Open, but the bigger story was who didn't win the title.

Retief Goosen, who had at least a piece of the lead after the first three rounds, struggled to a final-round 75, which cost him a chance at his first title since 2009.

Sergio Garcia bogeyed the final two holes and missed out on the playoff by one stroke. In a televised interview, Garcia bluntly said he didn't deserve to win because he didn't play well enough to do so.

Casey gave up his European Tour status to focus solely on the PGA Tour this season. Like Goosen, Casey was searching for his first tour title since 2009.

Finally, Johnson battled his way into the playoff, then made an outstanding birdie on the second extra hole to remain alive. If Johnson had won, it would have come in his third start after a six-month leave of absence from the tour.

Garcia and Johnson also would have soared up the list of favorites at Augusta had one of them come out on top.

What if?

Hahn, who had never won on the PGA Tour, matched Johnson's miraculous up-and- down birdie on the par-4 10th, the second playoff hole, then poured in a 25- footer for birdie at the 14th to beat Johnson. It was a great victory for Hahn, who gets into the Masters and several other events thanks to the win.

No offense to Hahn, but if any of the other four had won, the story lines would have been much better.

Goosen, a two-time U.S. Open winner, has had his back rebuilt since he last won. Late in 2012, he had disc replacement surgery and has slowly been playing his way back into contention since.

In tying for eighth, Goosen posted his fifth top-10 finish post-back surgery. He finished three strokes off the pace at the Sony Open in Hawaii earlier this year, and that was the closest he was to the winner in any of his previous top-10 finishes in the last two-plus years.

Riviera Country Club is known as a ball-strikers golf course, and Garcia is one of the purest ball-strikers on tour. Though he didn't have his best stuff, he scrambled to a Seve-like 68 in the third round to get into contention, but he couldn't duplicate that in the final round.

Poor drives on the final two holes of regulation cost Garcia the title, and a spot in the playoff.

Casey has been sharing time on the PGA and European tours nearly his entire career. The 13-time winner on the European Tour hadn't had a top-10 finish on the PGA Tour since tying for seventh at the 2011 Frys.com Open.

Johnson's return to the winner's circle may have brought more questions than answers. Reports stated he failed a drug test and was suspended during his leave of absence, but that report was denied several times.

The 30-year-old missed the cut by one stroke in his return to the tour at the Farmers Insurance Open. While playing with his future father-in-law, Wayne Gretzky, at the Pebble Beach National Pro-Am, Johnson shared fourth place at an event he has won two times.

At Riviera, Johnson's putter cost him twice. He had a 9-foot birdie putt in regulation to post 7-under, which would have given him the title, but the putt slid by the hole. On the third extra hole, Johnson played too much break and failed to convert his birdie effort to extend the playoff.

Having Goosen and Casey back in the mix makes the deep tour even deeper. Garcia and Johnson had a chance to join world No. 1 Rory McIlroy as the favorites heading into the season's first major, the Masters. They made strides in that direction yet couldn't get over the top.

What if?

NO STOPPING KO IN AUSTRALIA

Lydia Ko failed to break 70 in her four rounds at the Women's Australian Open at Royal Melbourne, but she did enough to win for the sixth time on the LPGA Tour.

Ko wasn't the only one to struggle on the difficult course. For the week, there were just five rounds in the 60s, two by Ilhee Lee, versus dozens of rounds in the 80s.

The teenager finished at 9-under par to win by two strokes over Amy Yang. Yang had a share of the lead after a lightning delay, but bogeyed two of the last four holes.

For Ko, her 9-under total was the worst winning score of her career. She had posted 10-under par or better in her previous five victories. With the win, Ko extended her lead atop the women's world rankings from 0.55 average points to 1.33 average points.

All of which makes her pre-tournament announcement even more shocking. Ko said that she plans to retire when she reaches 30 years old. It may be too early to think Ko could match Annika Sorenstam's 72 LPGA Tour wins, let alone Kathy Whitworth's tour-record 88 victories, but Ko already has six victories and won't turn 20 until April 2017.

Who know how many titles she'll have by then.

Ko has yet to win a major, but if she does so this season, she will easily break Morgan Pressel's record for youngest major winner in LPGA Tour history. Ko already has the most LPGA Tour wins for a player under the age of 18. Four more victories and Ko would shatter Nancy Lopez's record for youngest to reach 10 wins. Lopez did so at 22.

Ko has broken several records already in her career and will likely set many more. Before she retires at 30 to become a psychologist, who knows how often her name will be splashed across the record books?

MINI-TIDBITS

* With his win, James Hahn soared from 297th in the world rankings to 86th. After starting 2015 at No. 363, Hahn has soared 277 spots in the ranking. But he isn't the highest climber this year. Gary Stal has risen 344 places from No. 435 to No. 91. Stal has played six events this season, missing three cuts and finishing inside the top five in the other three, including a win in Abu Dhabi.

* Another interesting story line missed at Riviera was Vijay Singh. Playing the final round on his 52nd birthday and looking to become the second-oldest winner in PGA Tour history, Singh dropped four strokes in a three-hole span late on the back nine to fall from a share of the lead. The interesting angle is that Singh still has a lawsuit going against the tour for his suspension, which stemmed from his admitted use of deer antler spray in a Sports Illustrated story.