The election result in Schleswig-Holstein boosts her party's confidence ahead of the North Rhine-Westphalia state elections scheduled for next Sunday.
German Chancellor Angela Merkel's conservative party, the Christian Democratic Union of Germany(CDU), scored a big win on Sunday in elections in Germany's northern state of Schleswig-Holstein.
The result provides further evidence that Merkel is regaining momentum ahead of the federal election in September.
The victory came after the CDU had during the past two years lost a string of state polls, where voters punished her for her open-door immigration policy that allowed thousands of refugees into the country.
Her immigration policy has come under fire from her allies and rivals after a Berlin truck attack killed at least 12 people last year in December.
Voters in the small, northern state of Schleswig-Holstein on the Baltic Sea handed her CDU party 33.3 percent, while the centre-left Social Democratic Party (SPD) clinched 26.5 percent.
The results marked a blow for the Social Democrats who had earlier this year seen a surge in support since new leader Martin Schulz was chosen in February.
The blow to the Social Democrats' confidence came one week ahead of a far bigger regional vote in their stronghold of North Rhine-Westphalia, also Germany's most populous state, but it gave a boost to the CDU's hopes for next Sunday's polls.