Horne, son of former test batsman Phil Horne, completed his best first-class score, 93, albeit in his second game, before being part of a spectacular finish as legspinner Todd Astle took the last three Auckland wickets in one over to finish with five for 75, Auckland dismissed for 333.
Otago allrounder Sam Wells hit his fourth first-class century, and highest score, 118, to salvage some pride in their clash in Wellington.
Replying to Wellington's 302 for eight declared, and having been rolled for 98 in their first innings, Otago made 304, as Wells and Nathan Smith, with his first-class best of 59, put on 141 for the eighth wicket.
Wells batted five hours and hit 18 fours in his match-saving innings.
Rain interfered once again in the final day of Northern Districts' match against Central Districts in Hamilton.
ND, resuming at 89 for seven, reached 119 for nine in reply to CD's 274 for nine declared. Only 11 overs were possible yesterday.
Seamer Seth Rance finished with career-best figures of six for 31.
Eighth round games start next Tuesday, with Auckland hosting ND, CD playing Wellington in Napier and Canterbury hosting Otago.
• Points: Canterbury 73, Northern Districts 62, Wellington 60, Auckland 54, Otago 44, Central Districts 38.