Nobody missed a first serve yesterday in the 7-2 tiebreak that Federer won over Del Potro at WTF.
Federer went 5 for 5 (and lost no service points), Delpo 4 for 4.
Between them they served 3 aces, I think.
They were nearly as good in their Basel final a few weeks ago. Delpo won the first-set tiebreak 7-3. Nobody missed a first serve until Federer did, on the last point.
These two are definitely among the best at making first serves under pressure.