Worcestershire 473 (Waite 109*, D'Oliveira 89, Chappell 5-69) and 193 for 2 (Libby 104*, Azhar 62) beat Derbyshire 321 (Madsen 87, Godleman 70, Waite 4-50) and 343 (du Plooy 95, Godleman 86, Haider 65) by eight wickets
The pair shared a century stand at the Incora County Ground last season to save the match and this time their partnership of 139 from 191 balls set up an eight-wicket victory.
Azhar made 62 and Libby celebrated back-to-back hundreds at Derby with an unbeaten 104 from 140 balls to take Worcestershire to their target of 192 with 25.4 overs to spare.
Du Plooy and Zak Chappell had frustrated Worcestershire's hopes of wrapping up the innings quickly by batting through the first 15 overs of the morning.
After Chappell narrowly avoided being run out off the first ball, they took the lead past 150 with du Plooy driving Ben Gibbon straight and through the covers for boundaries.
Chappell had demonstrated his batting credentials in the first innings and he again showed good judgement to help his captain set a challenging target.
The stand was worth 89 from 137 balls when Chappell was undone by a smart piece of work from Gareth Roderick who brought off a leg-side stumping to give Joe Leach a third wicket.
Leach should have had a fourth in his next over but he spilled a straight-forward return catch offered by Ben Aitchison although it did not prove costly.
Aitchison chipped Tongue to mid on in the next over and the fast bowler took his second wicket of the innings when Sam Conners edged a drive to first slip.
It was now a case of whether du Plooy could get to his hundred but he was five short when Suranga Lakmal was beaten by a swinging full length ball from Tongue.
Ed Pollock came out intent on giving his team a fast start, driving Lakmal for two fours in the first over, but Aitchison angled one across him to have him caught behind off what became the last ball before lunch.
Pollock's departure did not alter Worcestershire's approach as Libby and Azhar played positively from the restart with Libby leg glancing Conners for four to bring up the 50 stand off 60 balls.
Although the occasional ball kept low, there was little in the pitch to encourage Derbyshire's bowlers with Libby and Azhar moving serenely towards victory.
The century stand came off 130 balls before Azhar turned Matt Lamb to fine leg for his fifth four to complete his fifty, his third at Derby in two seasons.
Chappell pinned Azhar lbw with a full length ball on the stroke of tea but the target was now down to 36 and Libby wasted no time in sealing victory.
He launched Lamb for a straight six and after completing his eighth first-class hundred for Worcestershire, dabbed Anuj Dal to the third man boundary for the winning runs.