With the Abt Audi team topping every test and practice session at the Tuscan track, Ekstrom was expected to challenge for the top spot and that he duly did, taking the German manufacturer's first pole of the season in 1:43.851.
"A good car, a good team, good weather, a good spirit and birthday – a perfect day," said Ekstrom.
"When you have such a great car, driving such fast laps is really easy. I am proud of the strong showing of the entire Audi team and I am happy with my first pole of this season."
Mugello
Hakkinen claims Mugello win
15/07/2007 AT 17:07
Behind 2004 champion Ekstrom, who took the ninth pole of his career, the Abt team were simply in a class of their own as Tom Kristensen - 0.214 seconds slower - Martin Tomczyk and Timo Scheider filled the front two rows.
Alex Premat made it five at the front for Audi as he took fifth in his year-old Phoenix-run version, with Canadian driver Bruno Spengler the best Mercedes driver in sixth in his AMG version.
His British team-mate Jamie Green followed him in sixth while Mike Rockenfeller and Christian Abt - two Germans at very different ends of the age spectrum - were next up for Rosberg and Phoenix Audi.
Daniel la Rosa completed the top ten for Mucke Mercedes with championship leader Bernd Schneider disastrously one place further back for AMG.
Britain's Paul di Resta was 12th in his 2005-spec Persson Mercedes with his team-mate Gary Paffett and Mucke driver Susie Stoddart 16th and 18th.
Mugello
Carroll dropped by TME
13/07/2007 AT 10:11