Trochowski's header was enough to secure victory for Hamburg
An away goal from Piotr Trochowski earned Hamburg a 1-0 win in their all-German Uefa Cup semi-final first leg against Werder Bremen.
Trochowski rose at the far post to head in a Guy Demel cross in the first half.
Hugo Almeida missed a couple of good chances for Bremen who contributed much to a superb game.
Shakhtar Donetsk came away the happier from the all-Ukrainian Uefa Cup semi-final first leg after grabbing a vital away goal in a 1-1 draw at Dynamo Kiev.
Hamburg, who eliminated Manchester City in the quarter-finals, made much of the early running against Bremen.
After 20 minutes Paolo Guerrero forced a superb fingertip save from Bremen keeper Tim Wiese with a rasping drive.
Eight minutes later, Hamburg were ahead when Demel curled over a deep cross which midfielder Trochowski rose well to meet at the far post to nod a header back across goal into the far corner of the net.
Bremen came out fighting in the second half and were almost level immediately when Diego crossed for Claudio Pizarro - on loan from Chelsea - but his header was misdirected wide.
Shortly after, a Clemens Fritz cross was spilled by Hamburg keeper Frank Rost but Almeida's follow-up header was directed straight at the keeper.
Twice within a minute around the hour, Ivica Olic was central to chances that could have extended Hamburg's lead.
Firstly, he ran clear down the left but delayed his shot and allowed Rost to save and then he escaped down the right and crossed for Jonathan Pitroipa but his header went wide.
Bremen pressed for an equaliser as the game wore on but Rost saved well from a Naldo drive and Pizarro skewered a good chance high and wide.
An important away goal from Brazilian striker Fernandinho earned Shakhtar Donetsk a draw in the first leg of the all-Ukrainian semi-final at the Valeri Lobanovskiy stadium against Dynamo Kiev .
Kiev took the lead after 20 minutes when Olexandr Aliev's long-range free-kick deflected off Ismael Bangoura's instep across goal to the far post where Chygrynskiy - marking Kiev striker Artem Milevskiy - unfortunately deflected the ball into his own net.
Prior to that, Shakhtar had been largely in the ascendancy but the goal gave Kiev the impetus to seize control of the match and for long periods dominate possession.
It was Shakhtar, though, who could have scored twice in the space of two minutes around the half-hour mark.
Willian lifts Fernandinho in celebration after his equaliser for Shakhtar
Firstly, Fernandinho cut inside and brought a neat save from Stanislav Bogush in the Kiev goal with a low shot, and then Luiz Adriano was just beaten to the ball by the keeper as he ran onto a through-ball.
In first-half injury time, Kiev's Carlos Correa unleashed a speculative 35-yard drive which took a deflection to wrong-foot Shakhtar keeper Andriy Pyatov but struck the outside of the post.
Kiev picked up where they left off in the second half and were close to extending their lead when Aliev found Milevskiy's head, but he was always stretching and could not apply sufficient contact to direct the ball goalwards.
Aliev then had a scuffed shot which found Ognjen Vukojevic free in the box but he could only steer a side-foot finish past the post.
Dynamo were made to pay for such wastefulness after 67 minutes when Shakhtar grabbed a precious away goal, forged entirely in Brazil.
Jadson unleashed Willian down the right and his cross was poked home by the sliding Fernandinho.
Kiev could have restored their lead but Aliev could not beat Pyatov after receiving a neat chipped pass from Milevskiy in the box.