The England captain, starting with extreme circumspection but playing with more freedom after the loss of his opening partner, Jason Gallian, showed that whatever problems Mark Taylor might have, he is in sound - if not always spectacular touch - going into the First Test.
After Lancashire had restricted the county champions' first-innings lead to less than a hundred, Atherton played very much the anchor role in that partnership.
Gallian has gradually emerged this season as a more adventurous batsmen. He reached 99 in under three hours before being trapped lbw by the persistent Gordon Parsons, who had previously had two appeals turned down.
That was the signal for Atherton to open up and complete a century, and he and John Crawley played with equal assurance to take Lancashire close to a lead of 200 before Crawley was also lbw to Parsons for 61 off the last ball of the day.
Earlier in the day, it had been Gallian's bowling that had much to do with keeping Leicester out of the dominant position for which they had seemed destined. Already with a first-innings lead, with five wickets standing, they progressed serenely enough, helped by the South African all-rounder Neil Johnson's belligerent 150, to 400 before their decline set in.
Johnson was trapped in front of his stumps by Ian Austin and the Leicestershire wicketkeeper, Paul Nixon, became the first man of the day to fall in the 90s when Gallian had him leg before.
Gallian's medium pace is more important to Lancashire this season in the continued absence of Wasim Akram and Mike Watkinson, and he finished with three wickets after also accounting for Parsons.
Allied to some forthright batting, it amounted to a highly influential performance that had much to do with putting Lancashire into a position where it is they, rather than the champions, who could dictate terms on the final day.