Landslide victory for opposition in Poland
Preliminary results show 41% of voters backed Civic Platform, beating the current Prime Minister Jaroslaw Kaczynski's Law and Justice Party by 9%.
“We need to give Poland more confidence, self confidence, but at first confidence between Poland and Russia and Germany and I hope it will be better than in the last two years,” Mr Tusk told Russia Today.
The turnout of almost 54% was the largest since the fall of Communism.
The election had been seen as a referendum on Prime Minister Jaroslaw Kaczynski. His Law and Justice Party have tackled corruption and poverty.
But relations with Russia have deteriorated. Poland objects to Russian gas pipelines through the Baltic; it's also irritated Moscow by being the possible location of a U.S. anti-missile defence shield.
But it's not just foreign affairs which have contributed to Mr Kaczynski's defeat.
Freelance journalist Alex Nowacki, who gave his vote to Tusk, thinks a lot of younger people were unhappy about Jaroslaw Kaczynski's policies:
“I think the rhetoric has been very traditional, not even conservative, just talking about the position of Poland in the world as if WWII was not yet over and also the extremely conservative attitude to many cultural questions such as abortion and gay rights”.
The Civic Platform may now be able to go it alone, but a coalition is more likely.