Without knowing clearly why you need to invoke two targets in this manner,
would it not be better to have the 2nd one have a dependency on the 1st
one? That way if someone invoked the 2nd without the first, you're
covered anyway.

 <target name="1st">
       <echo message="1st target invoked"/>
 </target>

 <target name="2nd" depends="1st">
       <echo message="2nd target invoked"/>
 </target>

[sean@se2 sean]$ ant
Buildfile: build.xml

1st:
    [echo] 1st target invoked

2nd:
    [echo] 2nd target invoked

But perhaps your build is more complicated than that. Using dependency is
the ant style though.