Alfie Mawson struck a last-gasp winner for the Blues but automatic promotion went to Bury on a dramatic final day.Wanderers did spend a period of the game in third spot after going ahead through Aaron Holloway and Nico Yennaris' strikes, with Morecambe beating Southend and Bury being held by Tranmere.
Town pulled themselves back into the game thanks to Sam Wood's own goal and Ryan Cresswell's header, but by the time Mawson lashed home in the 97th minute, Bury's promotion had been sealed with a 1-0 win.
There was mixed news on the injury front as Aaron Holloway returned to the side and Joe Jacobson made the bench after their absences, but Matt Bloomfield was only fit to be named amongst the subs after picking up a knock in training. Aaron Pierre came back into the side after suspension while Hogan Ephraim had a starting role in midfield as Fred Onyedinma and Max Kretzschmar dropped to the bench.
The game started quietly with the biggest roar reserved for news of Morecambe’s early goal at home to Southend, although Wanderers’ promotion rivals soon levelled to dampen the mood slightly.
Northampton had the first real chance of the game when Lawson D’Ath shot straight at Matt Ingram after a smart counter-attack involving Marc Richards and Ivan Toney, before the deadlock was almost broken by Paul Hayes who poked an effort against the crossbar with the keeper beaten after Aaron Pierre nodded the ball down into his path.
However, no sooner had Wycombe taken the lead that they made it two with a pair of superbly-taken goals. First Aaron Holloway thrashed home a volley after Paul Hayes’ shot had bounced into his path and moments later Hayes was the architect again, threading a through-ball for Nico Yennaris to latch onto and the on-loan Brentford man tucked it coolly past the keeper.
Aaron Pierre was then denied a third goal by the offside flag when Hayes touched a cross beyond the keeper, before Marc Richards came close to halving the deficit only for Matt Ingram to smartly save his header from a deep corner.
Northampton started the second half well and were denied by a smart reaction save by Ingram to keep out Lawson D’Ath, before the centre-half pairing of Mawson and Pierre continued to thwart any attack thrown at them as attentions in the stands turned to matters elsewhere.
For a short period, Wycombe found themselves in pole position with Morecambe leading against Southend, but Bury found the net at Tranmere to push themselves into third place.
Morecambe’s third goal left matters squarely in Bury’s hands as Northampton pulled one back on 67 minutes when Sam Wood diverted Ivan Toney’s cross past Ingram from the six-yard box.
The goal also came at the cost of an injury to keeper Matt Ingram who ended his long record of consecutive appearances as Alex Lynch came on for his Football League debut.
One of his first involvements was to pick the ball out of his net as Ryan Cresswell glanced home a long throw from Jason Taylor to make it 2-2, and the final whistle sounded at Prenton Park to clinch Bury’s promotion while the game at Sixfields was still going on.
Alfie Mawson struck home with the last kick off the game to ensure a fourth-placed finish for the Blues, which sets up a date with Plymouth Argyle over two legs for the right to face Southend or Stevenage at Wembley.