Great Britain's two lead boats - the men's coxless four and women's quad - suffered surprise defeats on day one of the second World Cup event in Lucerne.

With Colin Smith replacing the injured Andy Hodge, the four were third in their heat behind winners France.

They reached the semi-finals but GB manager David Tanner said: "Even with the changes we had to make, I still expected them to be in the pack."

Meanwhile the quad were second to China in a seeding race for Sunday's final.

We've done much better stuff than that in training so it's frustrating Steve Williams

Both crews won the opening World Cup regatta in Munich three weeks ago.

The other three gold medallists from Munich - sculler Alan Campbell, double Matt Wells and Steve Rowbotham and lightweight double Mark Hunter and Zac Purchase - all won their heats.

The world champion men's lightweight four - beaten by China three weeks ago - cruised into the semi-finals with a win in their heat.

But the men's eight - also second in Munich - face a repechage after being beaten by Germany. Alistair Heathcote replaced Smith in the stroke seat.

The men's four are missing Hodge and Tom James - who both have back problems - from their first-choice line-up. Tom Lucy kept his place after substituting for James in Munich.

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They were in the hunt up to the half-way point but fell behind the Netherlands and eventual winners France.

"It didn't have any life in it," said Steve Williams, the only remaining member of the crew that won Olympic gold four years ago.

"We've done much better stuff than that in training so it's frustrating."