Watching Manchester United under Ole Gunnar Solskjaer is like being on a roller coaster - just when you think you know what's coming, an unexpected drop or climb shakes you to your core.
Just ask Pep Guardiola.
The Catalan, who is masterminding yet another Premier League title win for Manchester City, just has not been able to crack the code when it comes to beating Solskjaer's United.
For all his shortcomings, Solskjaer sure knows how to win a derby match, even when the odds are stacked firmly against his side.
He is the only manager to have won more matches against Guardiola (four) than he has lost (three), and the first United coach to win their first three away games against their rivals from the east side of Manchester.
The latest, on Sunday, was perhaps the best of the lot, as the Red Devils lifted themselves from their recent lethargic displays to end City's 21-match winning run in style, winning 2-0 at the Etihad Stadium in a result that though unlikely to reignite their own title bid, again proves that when Solskjaer gets it right, they can beat any opposition.
If United lacked ideas in their back-to-back goalless draws with Chelsea and Crystal Palace over the past seven days, then they were keen to ensure there was not a repeat here, racing out of the traps to win a penalty after just 35 seconds as Gabriel Jesus tripped Anthony Martial inside the box.
Bruno Fernandes stepped up to net his 16th goal of the season, and within the first five minutes Luke Shaw should have made it 2-0, only to shoot straight at Ederson when well placed.
Having fallen behind for the first time in 20 games, City looked shellshocked, making uncharacteristic mistakes both in and out of possession, with usual talisman Kevin De Bruyne particularly culpable in giving the ball away.
After around 20 minutes the home side began to find their rhythm, but they found breaking down a stubborn United backline tough, and were limited largely to long-range shots.
The oft-criticised centre-back pairing of Harry Maguire and Victor Lindelof looked in formidable form, with stand-in goalkeeper Dean Henderson exuding confidence behind them in a performance that will lead to further questions regarding the future of David de Gea.
The England international was stretched on occasion, most notably by Oleksandr Zinchenko, while Rodri hit the crossbar for City, but the longer United kept City out, the more confident they grew.
No more so was that confidence on show than when Shaw picked up the ball in his own half shortly after the break, drove through the midfield before trading passes with Marcus Rashford on the edge of the box and firing into the bottom corner.
His performance was hailed as "absolutely incredible" by Solskjaer post-match, and was made even more impressive by the fact he was only passed fit to play after completing the warm-up.
Shaw is a totally transformed player from the one that would regularly be singled out for criticism by ex-United boss Jose Mourinho, with his attacking output having improved greatly over the course of what is turning into a superb campaign.
His average number of touches in the opposition half is up, just like his crosses and, most importantly, his goal contributions.
In his last seven games the left-back has provided a goal and four assists, and if - as Fernandes hypothesised this week - that is down to the increased competition from summer signing Alex Telles, then Solskjaer may think about adding competition in other key areas of the pitch.
That was certainly the idea when Edinson Cavani arrived in October, but if anything the Uruguay international's presence has forced Martial into his shell.
Here, though, the ex-Monaco man was excellent, as, having won the penalty, his movement played havoc with City centre-backs John Stones and Ruben Dias. Though he will feel he probably should have had at least one goal after shooting straight at Ederson when clean through in the second half, this was a much improved outing from the 25-year-old.
Martial's performance summed up United's whole display, taking advantage of a below-par City team to close the gap on the leaders to 11 points.
"We had to suffer, we suffered a lot, they worked their nuts off," Solskjaer remarked after the game. "I feel we’re a better team than what we were 12, 16, 18 months ago. We've improved massively, more robust and resilient and there’s more personality in the team."
Closing the gap on City further would be an almighty achievement by Solskjaer, but his United side are so wildly unpredictable it is dangerous to totally write them off.
Just ask Pep Guardiola.