Roger Federer suffered a shock defeat to German teenager Alexander Zverev in the semi-final of the Gerry Weber Open in Halle, Germany.
Federer, who was bidding to win his ninth Halle singles title and his fourth in a row, lost 7-6, 5-7, 6-3.
Zverev, 19, claimed the biggest win of his career, becoming the first teenager to beat Federer since 2006.
Federer will begin his bid for an eighth Wimbledon singles title later this month.
Federer had previously won 15 straight sets at Halle but Zverev, standing 6′ 6″ and ranked 38th in the world, dropped just four points on serve in the opener and won it 7-4 in a tie-break.
The Swiss hit back, claiming the first break of the match at 5-5 and serving out the second set.
But Zverev – born in Hamburg to Russian parents – broke in the sixth game of the decider and held on to win in just over two hours, becoming the first teenager to beat Federer since Andy Murray, then aged 19, in Cincinnati in 2006.