With a previous best league score of 62 for Sarisbury 1sts in 2018, the wicket-keeper hit an unbeaten 99 in a nine-wicket romp against Verwood at Potterne Park.
After opening partner Will Bolton (4) had fallen cheaply, Simon Orr (52 not out) helped Mills hurry Sarisbury to victory in the 27th over (of a maximum 45).
Earlier, Jon Floyd had become the sixth and final bowler used by Sarisbury - and he responded with a league best 5-38 off nine overs as the hosts were restricted to 5-38.
Portsmouth & Southsea were on the receiving end of Ben White lashing his maiden HL century.
The Shanklin & Godshill skipper came in at No 5 with his side 50-3. Alongside Ollie Niemiec, he proceeded to add 174 for the fourth wicket.
White smashed 17 fours and three sixes in a 106-ball innings and was still there at the close, unbeaten on 130. His career best remains an unbeaten 163, compiled in a Sunday friendly.
P & S were undaunted in replying to Shanklin’s 252-5 total, only falling 13 runs short when Dean Wilson was bowled by the final ball of the innings.
Romit Patel (47) and Sayeed Shahid (33) provided top order runs before Tom Wheeler came in at third wicket down and top scored with a 68-ball 60.
Rory Simpson (19) helped Wheeler add 44 for the sixth wicket, while skipper Matt Williams (17) helped him put on a further 56 for the seventh, but all in vain.
Opener Ryan Fitsell top scored for Fareham & Crofton 2nds for the second week running - but his side lost once again.
Fitsell had hit 42 in the season-opening loss to Shanklin, and compiled 65 as Fareham replied to Cadnam’s 193-8 target.
But opening partner Jon Tucker (24) - the pair put on 49 for the first wicket - was the only other batter to score more than 13 as Fareham subsided to 160 all out at Lambs Corner.