During the 2007 season, Bartel established himself as one of the premier ball-winning midfielders in the competition, averaging over 27 disposals per game—the second highest possession average in the league—and finishing amongst the top 10 within the league for total disposals (632), total handballs (291), total tackles (122), and tackles per game (5.3). After helping the Cats claim the McClelland Trophy, he was again nominated for the AFLPA Robert Rose Award as the game's most courageous player, and was also rewarded with his first All-Australian jumper.
Bartel's standout season continued when he was awarded the prestigious Brownlow Medal, winning with 29 votes—the highest number of votes ever by a Geelong medalist, and the third highest ever by any player under the current polling system—in a season that included eight best on ground performances. Despite missing the final two games of the regular season due to a burst appendix, Bartel also set an AFL record alongside teammate Gary Ablett, Jr., for polling the most combined votes ever by two players of the same club. In addition, the pair combined with teammate Joel Corey to set another AFL record for most votes ever polled by three players of the same club, at 61 votes. He capped off a fine season by winning his first premiership medallion when he helped Geelong claim the 2007 AFL Premiership. Bartel's 28 disposals, 5 marks, 5 tackles, and 2 goals in the 2007 AFL Grand Final helped the Cats claim an AFL-record 119-point victory over Port Adelaide.