It is undoubtedly the most well-worn footballing cliche.
However, Latics' Capital One Cup, first-round tie against Sheffield Wednesday was quite literally a game of two halves.
Latics played some decent football against npower Championship opponents and opened up a merited 2-0 half-time lead.
A cup upset in front of live television cameras from Sky Sports looked a distinct possibility at the mid-way point.
The second period was an altogether different story as Wednesday produced a stirring fightback inspired by former Latics' pair Jermaine Johnson and Chris O'Grady.
The pair scored the first three of Wednesday's four second-half goals, though in the early stages Latics had chances to put the tie beyond the reach of the visitors.
It was all part of the learning curve for new-look Latics with Paul Dickov admitted they had blown hot and cold.
Latics' manager said: "There are lots of positives to take from the first-half performance which is how I want the boys to play doing things right with and without the ball and we looked a very good team.
"Towards the end of the first half we get a little bit giddy, lost our shape and stopped doing the things which got us in front. The goals we conceded were sloppy from a team view and bad ones to concede which we have to look at as there were also a lot of negatives.
"We knew they would have a really good go at us in the second half as was proved."
Dickov added there is no reason to be alarmed as it is a new-look Latics' team as they will learn from the positives and also look at the mistakes they made in the second half.
And he also pointed out he was glad the mishap was in the cup and not the league which kicks off on Saturday at Milton Keynes Dons.
There was a debut for new loan signing Jordan Slew and it was a dream one as he gave Latics a seventh-minute lead with a clinical piece of finishing with a shot across the face of goal into the far corner from a James Wesolowski cut back after good work also in the build up from Cliff Byrne.
Wesolowski fired narrowly wide before Latics doubled their advantage in the 27th minute in controversial circumstances.
Wednesday appealed for a foul by James Tarkowski on Michail Antonio, but referee Eddie Ilderton waved play on as Lee Croft delivered a delicious right-wing cross for Jean-Yves M'voto to score with a bullet header.
O'Grady came on as a substitute after half an hour for the injured Gary Madine and he soon flicked on a header to release Chris Maguire who pulled his shot wide when it looked as though he could not miss.
Latics had a massive let off just before the break when Croft conceded a penalty for a needless trip on Antonio, but new Slovenian international Nejc Pecnik blazed high into the Chaddy End from 12 yards. There have not been many worse misses.
Wednesday halved the deficit in the 53rd minute when a speculative 25-yard drive from Johnson slipped under the body of diving keeper Alex Cisak
Either side of that goal, Latics could have opened a three-goal lead or restore a cushion of two as both Croft and Wesolowski were both denied by superb saves by former England keeper Chris Kirkland.
Had one of those chances been converted, it would have made Wednesday's task nigh impossible.
"We had two great chances early in the second half and, had one of those gone in, it might have been different," declared Dickov.
Wednesday rode their luck and equalised not long after the hour when O'Grady was left unmarked to plant a bullet header past Cisak from a Miguel Llera free kick.
O'Grady struck again with a delightful turn for such a big man to leave Latics' defence for dead as he scored again.
Remember how O'Grady, who never achieved success with Latics, returned with Rochdale and netted both goals in their victory at Boundary Park where he certainly relishes playing as an opponent.
The ever-dangerous Antonio's dazzling wing play was rewarded as he scored the fourth goal with four minutes left, an angled shot into the far corner of the net.
Latics had already brought on Connor Hughes and Matt Smith and in stoppage time Smith headed narrowly wide when a goal would have set up a nervous finish for the visitors.
Latics (4-4-2): Cisak; Byrne (Smith 82), Tarkowski, M'voto, Grounds; Croft, Furman, Wesolowski, M'Changama (Hughes 75); Slew, Simpson. Subs (not used): Brown, Bouzanis, Taylor, Millar, Winchester.
Sheffield Wednesday (4-4-2): Kirkland; Buxton, Llera, Gardner, R Johnson; J Johnson (M Jones 85), Semedo, Pecnik, Antonio; Madine (O'Grady 30), Maguire (Coke 40). Subs (not used): Bywater, Beevers, Mattock, Prutton.
The goals: Slew (7) and M'voto (27) for Latics. J Johnson (53), O'Grady (62, 70), Antonio (86) for Wednesday.
Bookings: Furman (61) for Latics. Pecnik (29) for Wednesday.
Attendance: 3,474 (1,230 visitors).
Referee: Mr E Ilderton.