Mark Webber re-captured the lead of the World Championship on Sunday, despite finishing the Italian Grand Prix in sixth place.
Webber had yet another poor start and then a frustrating race, gesticulating angrily as Williams' Nico Hulkenberg went off the track but refused to yield.
"We underperformed as a team," Webber told Belgian TV RTBF.
He might also have been disappointed to finish two positions behind his teammate Sebastian Vettel, despite the young German losing position earlier in the race with a coughing engine.
But with former championship leader Lewis Hamilton crashing out of the race after hitting Felipe Massa, it nonetheless means Webber takes a five-point title lead, albeit now with a much-reduced advantage over the chasing pack of contenders.
"The championship is not over," Hamilton told the BBC, "but it's mistakes like I made today that lose World Championships."
Fernando Alonso is the big points winner with his popular race win in front of thousands of Ferrari's ardent Tifosi.
The Spaniard was 41 points behind when he drove away from pole position, but that deficit is now halved to 21.
And early Monza leader Jenson Button was 35 points behind before Sunday's race, but by finishing second the gap to the leader is now just 22.
But it might have been a race win for the reigning World Champion, who openly questioned McLaren's decision to bring him in for his pitstop behind Alonso's Ferrari team that was ready to pounce.
"It was a little bit disappointing to find myself in that position," Button said, "but I don't think we had the pace of Ferrari today."
Schumacher Not Abandoning Comeback
Michael Schumacher's spokeswoman has played down rumours the seven-time World Champion is reconsidering his decision to return to Formula One.
The rumours were triggered at Monza by the German's former team boss Eddie Jordan, who now stalks the paddock as a pundit for British television BBC.
Jordan said on Saturday that he thinks Schumacher, 41, is in danger of vacating the Mercedes seat after spotting multiple team bosses, drivers and managers entering and exiting the German team's motor home at Monza.
"I've a hunch something fundamental has changed. I believe he is disillusioned and thinking of quitting," said the Irishman.
But Schumacher's spokeswoman Sabine Kehm hit back: "Michael has no plans to quit at the end of the year.
"When he entered into the whole comeback scenario, he was fully informed about the situation with the car. That's why he chose it to be a three year contract -- you cannot expect to come back and win straight away in that situation.
"Obviously he would have wished that the developments to the car improved its performance more than they did," Kehm said.
"But it is a three year project to build a winning team and he is in the middle of the process."
Jordan also said he has "hear rumours" that Mercedes team boss Ross Brawn might not be staying.
But Mercedes-Benz's Motor Sport Director Norbert Haug denied he is at loggerheads with Brawn.
"We are absolutely together working on next year's car," he said.