Kyle Coetzer hit an unbeaten 150 as Northamptonshire reached 320-4 at the end of the first day against Leicestershire at Grace Road.
That was a Championship-best for the 29-year-old opening batsman, who had scored only 133 runs in his previous nine innings.
Andrew Hall also made an unbeaten half-century as top-of-the-table Northants reached the close on a healthy total after being put into bat.
The hosts dropped no fewer than five catches, the most costly proving to be Coetzer, who was dropped on 25 when Nathan Buck failed to hold on to a sharp return catch off his own bowling.
Another major problem for Leicestershire was the number of boundaries they conceded.
When Coetzer brought up his century he had struck 19 boundaries in a 191-ball innings, while in total Leicestershire conceded a total of 202 runs in boundaries in the shape of 49 fours and a six.
After the early departure of Matthew Spriegel, trapped lbw by Alex Wyatt for seven, Coetzer and David Sales shared a stand of 65 in 24 overs.
Sales was dropped on 21, but had his off stump knocked back with Wyatt's first ball after lunch and was out for 32 that included six fours.
The impressive Coetzer then dominated a third-wicket partnership with Alex Wakely, who was dropped at slip off Ollie Freckingham early in his innings. But he hung around to share a stand of 74 before edging to slip off Buck for 18.
Robert Keogh was caught at mid-on for the same score off Michael Thornely with the total 200. But Hall then joined forces with Coetzer to punish the Leicestershire attack in the final session.
The fifth-wicket pair hammered 120 runs in 34 overs with Coetzer reaching his 150 off 277 balls with a six and 26 fours and Hall unbeaten on 65 off 112 balls with 10 boundaries.