Hahn wins Riviera playoff — Harrington 12 back
 James Hahn birdies the third extra hole at Riviera Country Club

James Hahn birdies the third extra hole at Riviera Country Club

James Hahn holed a 25 footer for birdie at the third extra hole to win the Northern Trust Open and seal his Masters debut.

It was a dream end to an enthralling final round at a rain-sprinkled Riviera Country Club that ended with Hahn (69), Dustin Johnson (69) and England's Paul Casey (68) in a three-way playoff.

They had finished level on six under par on a day when overnight leader Retief Goosen slipped to tied eighth after a 75 and Sergio Garcia (71) bogeyed the last two holes (and three of the last six) to finish in a four-way tie for fourth, one stroke outside the playoff on five under with Jordan Spieth (70) and the fast-finishing Keegan Bradley (68) and Hideki Matsuyama (67).

Casey came to the 18th at seven under par but bogeyed it after a sliced tee shot and set a target that could only be matched by Hahn and Johnson, who missed an 11 footer at the last to win his first event since returning from his "leave of absence." 

Goosen needed birdies at the last two holes to shoot 75 having run into trouble several times with a double bogey six at the eighth the beginning of his downfall.

All three players made par on the 18th in sudden-death before Casey was eliminated on the second extra hole — the 10th. He appeared to have the easier approach as he was left with a pitch straight up the green from the run off area on the left whereas Hahn and Johnson were both in the rough, further left and behind the bunker. 

While Casey pithed to 18 feet, Hahn and Johnson hit flop shots to around 10 and four feet respectively and after Casey had missed, the converted their birdie putts.

The survivors then went to the par-three 14th where Hahn made a 25 footer for birdie, punched the air and kept his head down as Johnson missed a 12-footer to stay alive.

Pádraig Harrington improved 12 places to tied 56th as he posted a level par 71 on a final day that brought lower temperatures and frequent showers.

After starting with a birdie on the 10th, Harrington missed from five feet to bogey the 14th and 17th. But having birdie the first and seventh to get into the red, he bogeyed the eighth.