Simon Katich struck 114 not out as Lancashire closed on 262 for four against Northamptonshire at Wantage Road.
Katich's fellow Australian Cameron White made 90 off 198 balls as leaders Northants were bowled out for 310 in morning with Kyle Hogg the pick of Lancashire's bowlers in taking four for 65.
On the eve of the first Ashes Test, Katich then struck a magnificent 114 not out off 182 deliveries, including 17 fours and one six, as the visitors ended the day trailing the hosts by 48 runs.
And with six wickets in hand, the momentum is now with them, although Azharullah did his best to keep the hosts in business by taking three Red Rose wickets.
Northants began the day on 275 for seven, with White resuming on 61 and wicketkeeper David Murphy on 28.
Murphy, however, was only able to add two runs to his overnight total before he was trapped lbw by Hogg in the eighth over of the day to break an eighth-wicket stand of 78.
Lee Daggett made just a single before he became another lbw victim to Hogg, who then finished Northants' innings by forcing White to edge to Lancashire wicketkeeper Gareth Cross.
Karl Brown then almost perished without scoring in the third over of Lancashire's reply as White put down a sharp chance at third slip off David Willey.
Luis Reece did not survive, though, as he edged Azharullah to Murphy in the eighth over before the same bowler's delivery clipped Brown's off stump to dismiss him for 13 in the penultimate over before lunch.
South Africa batsman Ashwell Prince helped get Lancashire's innings back on track with a bright 42 before he smashed Azharullah to Kyle Coetzer at square leg.
Katich then went past 50 off 89 deliveries but his next partner, Andrea Agathangelou, had his off stump sent tumbling by Willey's yorker.
Lancashire reached tea on 148 for four with the match still poised to go either way although a dominant unbroken stand of 116 between Katich and Luke Procter swung the contest their way.
Katich serenely completed his 56th century in first-class cricket off 156 balls by placing a four through point off Daggett.
Procter then went on to make a half-century of his own off 107 deliveries and he will resume tomorrow on 62 with his side looking to create a substantial lead.