Rikard Karlberg won the 72° OPEN D'ITALIA presented by DAMIANI following a play-off with Martin Kaymer on a dramatic afternoon at Golf Club Milano.
Kaymer had led by three shots on 21 under at one point but he collapsed on the back nine and required a birdie on the 16th to get alongside Karlberg, who had crept through the field with a 67, at 19 under.
Both men had parred the 18th all week and they did so again on the first play-off hole but Karlberg made birdie at the second attempt following a terrific approach over the trees to claim his first European Tour title.
“I thought I had a good chance this week because I have been playing very well lately but then when we were getting near to the end of the round I didn’t think I had done enough," he said.
"But then I managed the birdies at 16 and 17 which was good enough to get into the play-off. Then to go on and win against a player as good as Martin Kaymer in sudden death makes it very special.
“I had a perfect yardage for my second shot in the second play-off hole and I hit a lovely draw in there. Then I kind of knew the line from my previous putt and I hit a brilliant putt to make the birdie.
“It feels amazing to get my first win and it has been a pretty crazy year for me. I got married and now my wife is expecting twins in December!
"To get my first win on Tour and to give myself such a huge boost in my career is pretty special.” - Rikard Karlberg
Fabrizio Zanotti got off to a flying start as he made eagle from the greenside bunker on the first to leap into a share of the lead but Kaymer and Jens Fahrbring both birdied the first to get to 18 under.
Kaymer made another gain at the second to go out in front but the chasing pack were picking up shots of their own as back-to-back birdies from Zanotti moved him to 18 under after a dropped shot on the second while Romain Wattel made a gain on the third.
The German then notched five pars in a row as those behind him jostled for position but it was Joakim Lagergren who emerged as his main challenger with the low round of the day, 63.
The 23 year old made seven birdies and an eagle in his flawless effort to set the target at 18 under but he was not long off the course when Kaymer hit a wonderful approach to the eighth to get to 20 under par.
Zanotti dropped a shot to turn at 17 under and, while Lorenzo Scalise made five consecutive birdies and Matt Fitzpatrick was six under for the day, the players on course were struggling to put real pressure on the leader.
Fahrbring made a birdie on the the ninth to get to 18 under but playing in the group behind, Kaymer then birdied it himself to turn on 21 under.
He gave the shot back on the tenth after a poor chip and when he found some deep rough off the tee on the 13th, all of a sudden his lead was down to one shot.
Another bogey followed on the 14th and briefly there was a nine-way tie for the lead with Lagergren, Fitzpatrick and Danny Willett, who picked up four shots in his last five holes, all in the clubhouse.
Karlberg had not been a factor in the upper echelons of the leaderboard to that point after just a single birdie on the front nine but he picked up hots on the 10th and 14th and when further gains followed on the 16th and 17th, he was out in front on his own.
Fahrbring and Kaymer both then birdied the 16th to join him and when the former made a bogey on the last, the scene was set for the play-off.
Both men made routine pars on the 18th first time around but, despite Kaymer having better position the second time around, Karlberg got inside his ball and made an uphill putt for victory.
Seven players finished in a tie for third with David Lipsky and Lucas Bjerregaard joining Lagergren, Fitzpatrick, Willett, Fahrbring and Zanotti on 18 under.
Romain Wattel was then a shot further back after a disappointing closing 72 with Miguel Angel Jiménez and Roope Kakko alongside Scalise on 16 under in a top 11 that contained ten different nationalities.