Northamptonshire's bowlers were forced to toil in the Southampton sunshine for little reward on the second day of the County's Second XI Championship match against Hampshire.
Resuming on 123-2 in reply to Northamptonshire's 261 all out, the hosts powered on to reach 522-3 declared - with no fewer than three of their batsmen notching centuries.
Mike Roberts (165) and Michael Bates (179no) posted 194 for the third wicket, before Bates and Hamza Riazuddin (109no) added an unbroken 222 for the fourth.
Matt Spriegel claimed the wicket of Roberts - Northamptonshire's only success of the day - after Lee Daggett picked up both wickets on Tuesday evening.
Beginning their second innings 261 runs adrift, the County closed on 23 without loss - Spriegel and Rob Keogh the not-out batsmen.
Northamptonshire's first innings on Tueesday owed much to trialist Gary Knight, the top-scorer with 61 off 105 balls, and Muhammad Azharullah who shared a last-wicket stand worth 64.
Earlier, Karanjit Bansal (45) and Keogh (28) scored usefully but couldn't prevent the side slipping into trouble at 152-7 before the tail wagged.