A brilliant unbeaten 151 from Ed Joyce steered Sussex to a seven-wicket victory over Warwickshire early on day four at Edgbaston.
With just 57 more runs required heading into the final day, Irish left-hander Joyce ensured he started and finished the job, hitting the winnings runs in the morning session to give Sussex their first four-day win at the Birmingham venue since 1982.
Division One pacesetters Sussex have now won back-to-back matches to start the 2014 season, picking up 43 points, and look primed for a serious title challenge.
Only one wicket fell on day four, Rory Hamilton-Brown, who blasted 54, becoming Jeetan Patel's second victim when flicking to Jonathan Trott, but Matt Machan (27no) helped Joyce reach the 330-run target inside the first hour.
At Lord's, Chris Rogers and Sam Robson fired an unbeaten 112-run partnership to guide Middlesex to a comfortable 10-wicket win over Nottinghamshire.
The victory was ultimately set up by Middlesex's seamers after Notts had slumped to 224 all out having resumed on 184-5 overnight.
Steven Finn ended the match with nine wickets, four in the second innings to add to his five-wicket first-innings haul, as Middlesex responded perfectly to last week's defeat at Sussex.
Robson added 41 in the second innings to his mammoth 163 in Middlesex's first spell at the crease as he pressed his claims for a Test debut with England this summer.
Newly-promoted Northamptonshire escaped with a draw against defending champions Durham after their last-wicket pair survived the final nine overs.
Rob Newton (48no) and Azharullah (14no) combined to defy Durham's attack after coming together on 186-9 chasing a target of 319.
Seamer Graham Onions claimed 3-48 and leg-spinner Scott Borthwick (2-53) removed David Murphy and Maurice Chambers for ducks with successive balls to leave Durham one wicket away from forcing victory on a slow pitch at Wantage Road.
But they could not get the final breakthrough, Newton suppressing his normal attacking strokeplay during a 137-ball vigil as both sides emerged with 11 points, Northants finishing on 205-9.
Durham had earlier extended their second innings from 178-5 to 244 all out, Northants spinner James Middlebrook taking 5-62.
Yorkshire also batted out for a draw on the final day against Somerset at Taunton, although in far more comfortable fashion.
Somerset, on 530-9 overnight, were dismissed for 553 in the fifth over of the morning session, a first-innings lead of 103. Craig Meschede was left stranded on 59 not out, one of six Somerset players to make a half-century, but nobody went on to reach three figures.
Openers Adam Lyth (54) and Alex Lees (47) pieced together a 100-run stand to start Yorkshire's second innings and, with No 3 Kane Williamson following up with 57 not out, the visitors eventually declared at 193-4 at 5pm to bring an early end to a match that saw only 24 wickets fall across the four days.
Somerset's hopes of forcing victory were undermined by injuries to seamers Alfonso Thomas and Craig Overton, which prevented either from bowling on the final day.