Germany enjoyed their first golds of the championship thanks to a surprise javelin triumph from Linda Stahl and a victory by Verena Sailer in the women's 100 metres (11.10 seconds).
World champion Idowu had been laid low by a virus this year and was struggling to produce his best but it all came right at the Olympic stadium when on his fourth jump the 31-year-old set a personal best of 17.81M.
Tamgho had a best effort of 17.45 for the bronze behind. 2004 Olympic silver medallist Marian Oprea pulled off 17.51. Stahl headed up a German one-two in the javelin after a personal best of 66.81 on her penultimate throw meant she overtook Czech world record holder Barbora Spotakova, who had led from the first round with 65.36.
Olympic champion Spotakova, who has never won the European title, was then relegated to third when Christina Obergfoell also let rip with 65.58. As expected, the men's high jump final came down to a battle between Russians Ivan Ukhov and Aleksander Shustov, who beat his compatriot with a first-time clearance at 2.33 to equal the best in the world this year.