Ireland's David Gillick ran a season's best of 44.79 seconds at Barcelona's Olympic Stadium to qualify for the 400m final at the European Athletics Championships.
The Dubliner finished strongly to pip Britain's Michael Bingham (44.88) for the win this evening, with only two automatic qualifying spots on offer.
Gillick's time was just two-hundredths slower than the personal best he set last year in Madrid, and he seems to be coming into form at just the right time.
The 27-year-old, taking to the blocks in lane six, had stiff competition from Bingham and France's Teddy Venel inside him. He made a swift start and settled into his stride, putting himself right in the mix around the final bend.
Bingham led coming into the home straight, but the two-time European indoor champion responded to overtake him in the final metres.
Speaking afterwards, Gillick said: "I'm happy. I think it's quite important to win your semi-final, to get a better lane draw in the final.
"I was running blind in lane six, with the others inside me. But I stuck to my task and ran my own race, blinkered and just concentrating on what I could do.
"I worked hard down the back straight, stayed relaxed, kept my shoulders down and kept working away, and I caught Bingham on the dip."
Tullamore's Gordon Kennedy failed to qualify from the third semi-final, fading in the closing 100 metres for an eighth place finish (46.72).
Gillick's main rivals for the gold medal on Friday night will be the Michael Johnson-managed Bingham, France's Leslie Djhone and Belgian twin brothers, Jonathan and Kevin Borlee, who won the two other semis.
Jonathan ran 44.71 for a new national record and 2010 European leading time, while Kevin was a comfortable winner of Kennedy's race, clocking 45.32.
Meanwhile, Joanne Cuddihy failed to progress to the women's 400m final, coming home in 52.58 seconds for fourth place in her semi-final.
The Kilkenny woman broke the Irish record three years ago, lowering it to 50.73, and posted a best this year of 51.94.
Injuries have hampered Cuddihy's progress in recent seasons, however, and in top form, this was a field she could have troubled.