The forward, who became a father for the first time yesterday, headed in at the front post to rescue a point after Aaron Phillips had given Coventry the lead early in the second half.
David Dunn gave loanee Richie Wellens his first start for the club since rejoining the club on loan from Doncaster Rovers, whilst fresh from his contract extension yesterday, Richard Eckersley started in place of Joseph Mills.
After a minutes applause to remember former Coventry City manager Jimmy Hill, who sadly passed away following illness, the Sky Blues came out strong.
The first shot of the game came from the hosts after 30 seconds, but Newcastle loanee Adam Armstrong saw his shot deflected wide by defender, James Wilson.
The Sky Blues dominated the opening proceedings of the game but Latics were doing their best to frustrate their opponents.
Dunn’s men were restricting their opponents to shots outside of the box, with Ryan Kent shooting on 17 minutes but Tim Dieng blocked his shot.
Coventry defender Ben Turner was forced off the field midway through the first half with injury and he was replaced by Ryan Haynes.
That three minute break in play seemed to help Latics as they regrouped and went on the offensive.
Just before the half hour mark, Dieng was aggrieved as he felt he was fouled in the penalty area from a corner, but the referee waved away his penalty claims.
Liam Kelly opened up his body minutes later and struck from 30 yards which sailed over the crossbar as Dunn’s side got a foothold in the game.
However, Latics had to be wary of the counter attack, as O’Brien forced a good save from Cornell on 40 minutes.
Athletic continued to cause the Sky Blues problems and in additional time in the first half, Coventry goalkeeper Reice Charles-Cook was forced to punch away Mike Jones’ corner under his crossbar as the sides went into the break goalless.
Coventry came out firing in the second half and instantly put Latics under pressure.
A corner into the box two minutes into the half was cleared off the line by Mike Jones, however, from the following corner, Coventry took the lead.
Joe Cole’s delivery found Phillips at the back post and he nodded into the top corner to give the Sky Blues the lead.
However, Latics responded well and almost found a leveller minutes later.
Striker Jake Cassidy ran at the defence, cut inside and unleashed a powerful shot which the Coventry goalkeeper had to tip wide for a corner.
Latics were responding well to going a goal down and on 55 minutes, Danny Philliskirk headed over from eight yards following good football on the right between Brian Wilson and Carl Winchester.
Coventry felt they should have been awarded a penalty on the hour mark as Kent went over in the penalty box but the referee instantly said no.
Again Latics went forward and Philliskirk wriggled past three men but his through ball towards Cassidy was just too much.
It was Philliskirk that had Athletic’s next attempt on goal, shooting from 30 yards which the goalkeeper fumbled behind for a corner.
From that resulting set piece, James Wilson’s cross was inches ahead of an unmarked Riche Wellens at the back post.
Dunn made changes and brought on Dominic Poleon and Mark Yeates to add pace to the game and it was Latics that continued to attack.
With time seemingly running out, Winchester and Yeates started to cause more of a threat down the wings.
Michael Higdon was thrown on in the final minute to add strength and power in attack and he made an immediate impact.
His header deep into additional time was tipped over the bar by the goalkeeper from a Yeates cross, and from the following corner Latics equalised.
Jones delivered into the box and Philliskirk headed into the back of the goal to secure the point for Dunn’s side.
Coventry City: Charles-Cook, Phillips, Martin, Turner (Haynes 27’), Stokes, Vincelot, Bigirimana, Kent (Maddison 70’), Cole (Fortune 58’), O’Brien, Armstrong.
Subs not used: Burge, Di Kelly-Evans, Lameiras, Tudgay.
Oldham Athletic: Cornell, B.Wilson, J.Wilson, Dieng (Higdon 89’), Eckersley, Wellens (Yeates 75’), Kelly, Jones, Winchester, Philliskirk, Cassidy (Poleon 75’).
Subs not used: Coleman, Mills, Vassell, Fulton.
Goals: Coventry City (Phillips 48’) 1-1 Oldham Athletic (Philliskirk 90+3’)
Attendance: 15,419 (259 visiting supporters)