HOLD UPDATE 2-Olympics-Boxing-Finnish mum ends Irish champion's hopes

* Potkonen beats 2012 champion Taylor in quarter-final * Irish lightweight loses on points (Adds semi-finals line-up) By Alan Baldwin RIO DE JANEIRO, Aug 15 (Reuters) - Mira Potkonen, a 35-year-old Finnish mother of two daughters, dumped Ireland's 2012 Olympic lightweight champion Katie Taylor out of the Rio Games on Monday in the first shock of the women's boxing tournament. The split points decision in the Finn's favour left Ireland, winner of four boxing medals at the London Games, with only bantamweight world champion Michael Conlan remaining in contention. The quarter-final was five-times world champion Taylor's first fight in Rio after a bye through the first round. Potkonen, who meets China's Junhua Yin in her semi-final, is now assured at least a bronze medal. The other semi-final will be between France's Estelle Mossely and Russian Anastasia Beliakova, who beat Mikaela Mayer of the United States to secure her bronze. "It's very hard to talk about," said a subdued Taylor, trying to stay composed after the split decision against her but with tears in her eyes and long pauses as she spoke. "It was a close fight and congratulations to her. But I should really be beating those girls." Taylor was ahead 29-28 on the judges' scorecards after the opening round but dropped two points behind after the second as Potkanen landed some telling blows. The judges were split after the third, two scoring the round 10-9 to Taylor and the third giving it to the 35-year-old Finn to reduce the advantage to a single point. The fourth round ended with the scores tied, one judge's tally pointing to Taylor 39-37 and another 39-37 to Potkanen with a third scoring it 38-38 and having to make the final decision. "It's just very, very disappointing," said Taylor, whose future in the sport at 30 looks uncertain. "I was well prepared coming into the fight. "I left no stone unturned in preparation for this competition. I really believed I'd come home with the gold medal but it wasn't to be." Taylor had struggled to qualify for Rio, beaten in a European qualifier, and never got into gear against a familiar opponent who offered no real surprises. "It's been a very, very tough year for sure. A very challenging year," she said. "Suffered so many losses. I'm sick of losing at this stage this year. I don't know what I'm doing wrong really. "I really felt I was prepared for every opponent here this week and it's just the way it goes." At the London 2012 Games, Taylor was one of the faces of women's boxing as the sport made its Olympic debut, and she drew a huge following at home on her way to the gold. (Editing by Tony Jimenez and Neil Robinson)