Wanderers have had some great days in reaching 5000 league games and this was another one.
A thumping win at the home of one of one of their top-six rivals was the perfect way to mark becoming the fifth club to reach the milestone after Burnley, Preston, Wolves and Derby.
In doing so, Ian Evatt’s history-makers went above Derby to fourth place in League One.
And a red-letter occasion which brought Wanderers' biggest away win since 2001 was made even more special by a couple of individual firsts.
Captain Ricardo Almeida Santos – back at his former club – scored his first goal for Wanderers on his 118th appearance to set the Whites on their way to a fourth successive league win.
He also added the fifth for good measure.
And in between time, top scorer Dion Charles claimed a nine-minute hat-trick in an electric spell either side of half time in which the Whites emphatically killed off a Peterborough side also looking to add to a three-game winning streak.
Charles scored twice from the penalty spot and added the goal of the game to move to 16 goals for the season.
The Northern Ireland international also became the first Wanderers’ player to score a hat-trick since Joe Mason in September, 2014 and the first to claim a treble away from home since John Thomas in 1988.
In Wanderers’ long history, it was a day to remember.
With Conor Bradley starting a two-match ban to miss only his second league game of the season, Wanderers again re-shuffled their back line to give a debut to on-loan Manchester City defender Luke Mbete.
Shola Shoretire – borrowed from the other half of Manchester – moved into a more advanced role as Kieran Lee also earned a start.
And it was a foul on Shoretire that led to the opening goal with just over 10 minutes gone.
Almeida Santos was unable to turn in Aaron Morley’s free-kick at the first attempt but when Gethin Jones sent the ball back towards goal, Santos flicked out a leg to steer it home and end his long wait.
It was frenetic stuff as neither side gave an inch in a what felt like a heavyweight clash, Santos having to make a vital block at the other end and James Trafford gathering an effort hit straight at him by Ephron Mason-Clark.
Wanderers also carried a threat as they pressed from the front and when Lee pulled the ball back for Shoretire on the half-hour, the teenager saw an effort blocked before Morley fired a long range over the top as the Whites kept the pressure on.
It always felt another goal wasn’t far away and, critically, it went Wanderers’ way just before the break.
Peterborough’s leading scorer Jonson Clarke-Harris had just headed an excellent chance wide following a corner when the Whites launched another telling counter-attack.
Mbete’s combination with Declan John opened up the Posh defence and when Mbete pulled the ball back for Shoretire, he was tripped by Nathan Thompson as he prepared to shoot.
It was a straight-forward decision for referee Lee Swabey to point to the spot and after checking the ball had been correctly placed, he allowed the ice-cool Charles to step up and send on-loan Burnley goalkeeper Will Norris the wrong way.
That was Charles’ fourth goal in six games and he didn’t have to wait long for the next as two more within the opening five minutes of the second half secured his first treble for the Whites.
The hat-trick was completed from the penalty spot after Shoretire had been barged over in the middle of a shell-shocked Peterborough defence.
But the second was a magnificent team goal that summed up the Whites’ scintillating display.
When Santos swung the ball wide for Jones, the Wanderers’ vice-captain showed desire, determination and an outstanding technique to win the ball in the air and race forward to deliver a perfect cross for Charles to meet on the volley and crash into the back of the net.
The Wanderers’ fans were in dreamland as they chanted for a fifth goal, although at the other end it was all about trying to secure another clean sheet and an excellent save by Trafford to keep out a Clarke-Harris’ free-kick prolonged that prospect.
Charles and Shoretire were then given a breather with half an hour to go after a superb afternoon’s work but the fun didn’t stop there.
Having got a taste for scoring, remarkably Almeida Santos did it again.
And this time there was no querying the quality of the finish as he rammed the ball home with a precise side-footed strike from six yards out after Wanderers had re-cycled a corner to end a memorable afternoon on a high.
Wanderers: Trafford; Toal, Almeida Santos, Mbete (Isgrove 79); Jones, Morley, Dempsey, John (R Williams 79); Lee (Sheehan 79), Shoretire (Jerome 63), Charles (Adeboyejo 63). Substitutes: Dixon, Sheehan, Isgrove, R Williams. Khumbeni.
Booked: Charles, Almeida Santos, Shoretire
Peterborough United: Norris; N Thompson (Knight 67), Kent, Edwards, Butler (Ogbeta 52); Ward, Kyprianou, Taylor (B Thompson 75), Mason-Clark; Poku (Jones 75), Clarke-Harris (Tshimanga 68). Substitutes: Blackmore, Burrows.
Booked: Kyprianou, Poku, Taylor
Referee: Lee Swabey
Attendance: 9,247 (1,725 Bolton)