The Stags striker pounced in the 86th minute after Chris Clements' swerving 25-yard was tipped onto the woodwork by visiting 'keeper Matt Ingram.
Paul Cox's team, who controlled the match for long periods, would have snatched all three points later had Ingram not produced a splendid full-stretch diving save to keep out Clements' deflected 30-yard drive.
Wycombe took the lead early on, as Skipper Stuart Lewis’ 25-yard strike found the back of the net, before Josh Scowen doubled the visitors’ lead in the 48th minute.
Nevertheless, Stags kept piling on the pressure, as Lee Stevenson pulled a goal back from close-range, before Palmer grabbed Stags an all-important equaliser in the 86th minute
The Stags named an unchanged starting 11 from our draw at Portsmouth last weekend, although midfielder Sam Clucas was on the bench following his return from injury.
With heavy rain and dramatic thunder and lightning 30 minutes before the game, Groundsman Michael Merriman was forced to roll a certain section of the pitch which passed a late inspection.
Mansfield started the game as the better side, enjoying majority of the possession, although they were unable to find their way through the Wycombe defence.
Two minutes in, the Stags had their first big scare as Ritchie Sutton’s back pass held up on the wet surface, resulting in goalkeeper Alan Marriott rushing out of his goal to clear the ball away to safety.
On five minutes, Mansfield created their first opportunity of the game, as Darryl Westlake found his way passed his opposition defender, before firing his effort straight at Matt Ingram.
Despite good spells of pressure from our side, it was the Chairboys who took the lead on eight minutes, as skipper Lewis’ 30-yard strike found the top right-hand corner of the net, leaving Marriott rooted to the spot.
Cox’s men reacted well to going 1-0 down, as Anthony Howell turned his man before cleverly running into the penalty-area giving Stevenson an opportunity to cross to Matt Rhead, who had his shot from an acute angle superbly palmed away by Ingram.
Stevenson was then in the thick of the action again as he met Clements’ cross with a well-timed volley which went straight at the Wanderers shot-stopper.
Stags kept knocking on Wycombe’s door, as they went close from two corners in the space of one minute. The first corner from James Jennings went through a sea of bodies before the second one was headed just inches over by defender Ryan Tafazolli.
After 33 minutes, Mansfield tested Ingram yet again, with Stevenson’s pass finding Ross Dyer in the centre, who rifled his effort goalwards from 25 yards, as the Wycombe goalkeeper pulled off a fingertip save, giving our side their seventh corner of the match.
Despite a quiet end to the first half with the Stags 1-0 down, Cox’s men would have gone into the break feeling like they were the better side having created more chances on goal.
The Stags started the second-half brightly as Jennings’ free-kick was flicked on by Dyer, before Stevenson’s header clipped Wycombe’s bar. However, the referees’ assistant put his flag up for offside.
In the 48th minute, Wycombe doubled their lead as Nick Arnold’s pin-point ball found Scowen, who volleyed home passed the helpless Marriott from close-range.
Three minutes later, manager Cox made his first change of the afternoon, as he introduced Clucas for Dyer, as the midfielder made his return to the first team following an ankle ligament injury picked up in mid-December.
On 54 minutes, Stevenson tried his luck from outside the penalty-area, but his shot deflected off Leon Johnson for another corner.
From the resulting corner, Mansfield pulled a vital goal back to make it 2-1, as Howell’s low shot from inside the penalty-area hit Stevenson, before the midfielder quickly spun to slot home from close-range.
The goal appeared to spring Stags back into life as Jennings’ cross on 58 minutes found Clucas, whose header went wide of Ingram’s goal.
Wycombe then created their second chance of the second-half as Matt McClure’s drilled free-kick was put over by defender Johnson from close-range, which was arguably a key chance for the visitors to restore their two-goal lead.
Our side continued to pile on the pressure, desperately searching for an equaliser, as Clements’ cross was importantly cleared away by Johnson for a corner in the 73rd minute.
Clements then tried his luck from a 30-yard free-kick, but his speculative effort sailed over Ingram’s goal, causing the Chairboys’ goalkeeper no cause for concern.
Mansfield made their second substitution on 80 minutes, bringing on Palmer for skipper John Dempster, in order to find an equaliser.
Substitute Palmer made an instant impact six minutes later, converting from close-range to grab Stags an all-important equaliser, making it 2-2, following Clements’ initial effort crashing against the cross bar.
Clements was determined for his team to come away with all three points, as his 25-yard strike in the 90th minute was saved by a full-stretch Ingram.
Nevertheless, despite Marriott denying a late Wycombe chance, both teams shared the spoils in an entertaining 2-2 draw.
Attendance: 2,789 (258 away supporters).