Dinesh Mongia fired an unbeaten 158 to put Leicestershire in a commanding position against Essex in the division two County Championship at Chelmsford.
The left-handed Indian was typically pugnacious, driving and pulling with authority during his 246-ball knock, which was studded with 20 fours and a six.
Mongia, who came in after the departure of opener DDJ Robinson (53) at 97 for two, shared a 170-run partnership for the third wicket with another centurion HD Ackerman (111) to help his side pile up 392 for five from 104 overs on Wednesday.
At the close of a fruitful first day's play, PA Nixon (18) was giving company to Mongia at the crease after the visitors elected to bat on a batsmen-friendly pitch.
For Essex, left-arm spinner Tim Phillips was the most successful bowler, claiming two wickets for 57.