Mercedes should be worried by the Sebastian Vettel who powered to victory at the Singapore Grand Prix.
Toto Wolff is probably correct in predicting some form of normality will return in Suzuka, away from the unique and bumpy Marina Bay circuit Mercedes should expect to return to the top of the pile unless something truly seismic happened to its power unit and W06 chassis on the flight from Italy to Asia. But Vettel's performance in Singapore was a warning of the sort of challenge the world champions could face on a regular basis in 2016 if Ferrari matches its recent progress over the winter.
Though it was his third win of the season, there seemed to be something a touch fortuitous about Malaysia and Hungary - on both occasions the storyline was as much about what Mercedes did to lose the race than what Vettel did to win it. Not so in Singapore. Mercedes was off the pace, but from the start of Friday practice Vettel was the pick of the bunch at a circuit where he's now won four of the last five races.
There is something very special in watching Vettel at Marina Bay. It is no coincidence that his best result of his forgetful 2014 campaign came under the very same floodlights when he finished second to Lewis Hamilton. The twisty street circuit suits Vettel's driving style perfectly - the tight corners favouring the short and sharp turns of the wheel he employs to perfection before getting back on the throttle as early as possible.
Nico Rosberg said Vettel's Ferrari was on a "different planet" on Saturday and it was hard to disagree with the Mercedes driver when watching the on-board video of the pole lap. Through the first and final sectors Vettel was especially brilliant, feeling so confident with his car he seemed to get closer and closer to the wall at Turn 21 without making contact. The margin of half a second to Daniel Ricciardo in qualifying said everything you needed to know.
This was as good as we've seen Vettel since his move to Ferrari. There were some ridiculous things written and said about Vettel while he struggled with the RB10 at Red Bull last year, that somehow his poor form was proof his four world titles had been gifted to him by a superior machine. On Sunday, Vettel looked like the man who won nine races in a row in 2013 and reminded us all why he is a four-time world champion, storming out of the blocks early and then managing the pace of the race when he needed to ahead of Daniel Ricciardo, a man who deserves equal plaudits for the job he did to split the Ferraris on both Saturday and Sunday.
How much did the second safety car save Vettel a nervier finish? Red Bull boss Christian Horner thought it robbed Ricciardo of at least a chance to challenge for the victory.
"I think we could have taken the fight a bit closer to Ferrari because our car was definitely softer on the tyre, so we were more competitive at the end of the stint," Horner said. "At both ends of the stint we had a Virtual Safety Car or a safety car and that gave Ferrari a bit of breathing space, a free pit stop effectively, and we didn't have the opportunity to undercut them or put them under pressure at that point in the race. It would have been interesting to see without the safety cars how it would have panned out."
However, there was one inescapable conclusion to take from Vettel's win that Horner himself alluded to.
"Today was classic Sebastian Vettel. Managing the race from the front, looking after the tyres, not making any mistakes."
With all the signs pointing towards Ferrari continuing its relentless pursuit of Mercedes into 2016 and narrowing the gap further still, the Italian team has a driver back to the height of his powers ready to take it back to the promised land. Sergio Marchionne's statement after the win was a shot across the bows of Mercedes: "I promise them [the tifosi] this race is not just a one-off but a huge step forward on our road back to staying at the top and hearing the Italian national anthem played a lot more often."
Vettel has become Ferrari's new favourite son in just nine months and, after his drive in Singapore, he seems like the perfect man to continue leading the team's charge back to the top.
The kids are alright
How about those Toro Rosso rookies? On a day which ended with the news a certain Venezuelan pay driver has another season in F1, it's refreshing to see the young drivers coming through the ranks continue to shine.
The mini team order controversy at the end of the race should not overshadow the fighting performances of both Max Verstappen and Carlos Sainz, which ended in thrilling late charges through the field. The two safety car periods aided Verstappen's fight back from a lap down but from that point on he took positions with clinical ruthlessness you would expect from a more experienced driver. His move on Romain Grosjean was the pick of the bunch, forcing the Lotus man to go defensive at Turn 14, taking a better exit out of the corner and outbraking him into Turn 16 for eighth place. Not to be out-done by his team-mate, Sainz then barged past Grosjean at Turn 1 a lap later as the Lotus man continued to struggle with his tyres.
Given his race to that point, you can understand Verstappen's reluctance to heed to Toro Rosso's team order at the end of the grand prix.You could argue it shows immaturity, you could argue it shows the ruthless streak an F1 driver needs to be champion. After all, who was the last Red Bull driver to ignore a team order and show little remorse for doing so afterwards? Sebastian Vettel himself.