A late Pawel Abbott penalty denied Wanderers a deserved three points at Boundary Park.
The Latics striker struck as the clocked ticked towards full-time, after captain Adam Hinshelwood was adjudged to have handled in the area.
This was after Reuben Hazell had headed the hosts in front just before the half-hour mark from an inswinging Kieran Lee free-kick.
Matt Harrold levelled matters on 42 minutes from the spot before former Oldham man Kevin Betsy looked to have handed Wycombe a vital victory in their fight for survival from 25 yards out.
But Abbott stepped up to smash the ball home and salvage a fortunate point for Dave Penney's side.
Following the tepid nature of the previous week's stalemate with Carlisle United, manager Gary Waddock sought to inject some tempo and power into the side by making three changes to the side, bringing Gareth Ainsworth, Kevin Betsy and Stuart Beavon into the starting line-up.
And it seemed to have a positive effect in the opening exchanges, with Wycombe finding their rhythm with comfort on a chilly day in the north-west.
Ainsworth was picked out by Dean Keates with a deep free-kick inside five minutes, but the winger -returning after a three-match suspension - could only divert the ball into the arms of keeper Dean Brill.
Four minutes later, right-back Julian Kelly tested the keeper's handling with a firm left-footed drive from 25 yards, but Brill was equal to it and claimed the ball with relative ease.
Oldham's main attacking threat came via the long ball towards target man Pawel Abbott, but he turned provider on 12 minutes with a cross from the left which was diverted towards Chris Taylor. However, the midfielder's header lacked conviction and was easy for Tom Heaton to hold on to.
Dale Stephens and Craig Woodman both saw efforts fly wide for either side as clear-cut goalscoring chances were hard to come by, and so it came as somewhat of a surprise when Reuben Hazell handed the home side the lead on 29 minutes.
Kieran Lee's deep free-kick from the right wing was flicked on unknowingly by Matt Harrold into the path of Hazell, who made no mistake in glancing the ball into the net from four yards.
It came as a blow to the visitors, but after a short period of being pushed onto the back foot, Wycombe came back purposefully, and after Dean Keates saw a free-kick sail wide, Kevin Betsy was denied a chance to equalise when Deane Smalley made a late headed clearance at the back post.
From the resulting corner, Matt Harrold's towering header was cleared off the line by Danny Whitaker, and if Wanderers' supporters could sense a goal coming, their intuition was spot on.
Another Keates corner caused panic inside the box and when Ainsworth's overhead kick was deflected to the edge of the box, John Mousinho's powerful drive was blocked by a defender's hand, prompting referee Eddie Ilderton to point to the spot.
Oldham's staff and players alike were furious with the decision, but Harrold kept his composure to slot the ball home, and the two sides went into the break all square.
And parity didn't last long. Just four minutes after the break, Kevin Betsy broke forward from the halfway line and drove goalwards from fully 30 yards, seeing his effort squirm under the arms of keeper Dean Brill and into the net.
It was a particularly poignant moment for Betsy, proving a point against his former employers and to manager Gary Waddock after being dropped last week, but more importantly, it gave Wycombe the lead in a crucial game in the battle to beat the drop.
Three minutes later, Harrold could have extended the lead after superb work by Stuart Beavon on the left channel, but the tall striker could only guide the ball into the keeper's arms after Beavon's cutback.
At the other end, Deane Smalley looked to get his side back on level terms with a looping header from a corner, before manager Dave Penney reacted by bringing on midfielder Dean Furman for striker Kiegan Parker.
Wycombe were beginning to get a real grip on the game, and with the constant attacking threat provided by the outstanding Ainsworth, there was always the chance of the Blues extending the lead.
But the Latics had a golden chance to equalise on 72 minutes when Kieran Lee's square pass across the box was met by the boot of Pawel Abbott, whose toe-poke was straight at Heaton when he should have done better.
Tom Eaves and Kirk Millar were both brought on as one last throw of the dice for the Latics, while for the Blues, Alex Revell came on in a like-for-like swap for Matt Harrold up-front.
Gareth Ainsworth's excellent performance was then brought to a close on 84 minutes when Gary Waddock brought on Kevin McLeod to offer fresh legs in midfield, but the game turned back in Oldham's favour when Pawel Abbott levelled from the spot on 89 minutes.
A firm drive from the edge of the box struck Adam Hinshelwood, and the referee - perhaps keen to make up for the controversy of his earlier penalty decision - pointed to the spot, accusing Hinshelwood of handball. Abbott converted, and two crucial points had been swiped away from the Blues.
Jon-Paul Pittman came on for Stuart Beavon in one last gamble, but there was no time a winner, and the gap between Wycombe and safety remains seven points.