Rob Jones, George Lavelle and Sam Perry all hit centuries as Lancashire's Second XI piled on the runs on the opening day of their four-day friendly against Hampshire.
There was an uncontested toss as the visitors chose to bowl first at Northern CC and Jones crashed 153 from just 87 balls inside the opening session.
The opener struck 20 fours and seven sixes, as he and partner George Balderson (54) put on exactly 200 for the first wicket.
When Balderson and Jones departed in quick succession, Lavelle and Perry came together to add a further 218 to the total, taking the Lancashire score to 428-2.
Perry went late in the day for 107, but Lavelle was unbeaten at the close on 113, with Stephen Parry yet to score.
The Red Rose will resume Day Two on 459-5.