- Lewis Hamilton started on pole position but disastrous start saw him drop down to sixth place at Monza
- The reigning world champion held nine-point lead over Nico Rosberg in title race prior to Italian Grand Prix
- German Rosberg, the Brit's Mercedes team-mate, clinched vital victory to close the gap to just two points
- Four-time champion Sebastian Vettel claimed third place for Ferrari at Maranello outfit's home race
- Click here for all the latest F1 news, features and points tables
As the lights went out, he got off the line in the first split second as well as anyone. But almost immediately he was like a man wading through treacle. The rest of the field closed on the world champion left, right and centre.
From pole position, Hamilton plunged to sixth by the first corner, and the script had been ripped apart.
Nico Rosberg crowd surfs with his Mercedes team in parc ferme after clinching victory at the Italian Grand Prix on Sunday
Rosberg shadow boxes in front of a camera man having trimmed Lewis Hamilton's championship lead down to two points
Rosberg jumps for joy after cruising to a much-needed victory at Monza from Lewis Hamilton (left) and Sebastian Vettel
Rosberg celebrates on the podium in front of the Italian Grand Prix fans who packed the pit straight to watch the ceremony
The Monza podium overhangs the circuit and is a driver's favourite as it looks over the passionate Tifosi at the Italian GP
President of Lombardy Roberto Maroni removes a flare thrown on the the podium shortly before the drivers emerged
F1 ITALIAN GRAND PRIX RESULTS AND CURRENT WORLD CHAMPIONSHIP STANDINGS
What happened to Hamilton in those fateful few seconds was unclear, though he admitted over the radio to human error. However, it is not the first time this season that the Brit has been slow into the first corner.
Back in the Mercedes garage, team principal Toto Wolff could be lip-read letting out a mild four-letter expletive. Why? And how, he must have thought?
Mercedes chief Toto Wolff (left) reacts alongside Dieter Zetsche following Hamilton's disastrous start to the Italian Grand Prix
Rosberg cruised to a win at the Italian Grand Prix after taking advantage of team-mate Hamilton's nightmare start
The German took full advantage of Hamilton's start to claim a seventh win of 2016 and close the gap on Hamilton in title race
Reigning world champion Hamilton started the Italian Grand Prix on pole position but endured a disastrous start at Monza
Hamilton dropped down to sixth place after a poor start in Italy with Mercedes team-mate Nico Rosberg moving into first
Rosberg was straight into the lead from second on the grid. The German comfortably opened up an impregnable lead. With 10 laps down he was 11 seconds up on Hamilton as he finally passed the Williams of Valtteri Bottas to go fourth.
At this point the two Ferraris separated the two Mercedes.
But the home cars were planning on pitting twice as opposed to Mercedes' one-stop strategy. That allowed Hamilton up to second, where he finished with Sebastian Vettel ahead of his Ferrari team-mate Kimi Raikkonen in fourth.
The start of Sunday's entertaining Italian Grand Prix sees Hamilton drop down the field as Rosberg moves into the lead
A general view of the start of Sunday's Italian Grand Prix as Hamilton is overtaken by five Formula One rivals at Monza
Rosberg, Sebastian Vettel, Kimi Raikkonen, Valtteri Bottas and Daniel Ricciardo all cruised past Hamilton at the start
Hamilton, who held a nine-point lead over Rosberg in the title race prior to the Italian Grand Prix, overtakes Williams' Bottas
Rosberg's victory was his seventh of the season, second in succession, and gave him his 50th podium in a career that started in Bahrain in 2006. Bring on Singapore a fortnight hence.
'One and two in Monza!' said Mercedes team principal Toto Wolff. 'This is the most prestigious track. It is Ferrari land. Awesome. You may think it was boring to watch but for us it was fantastic.
Further back Englishman Jolyon Palmer was unlucky to have his race ended early on by Sauber's Felipe Nasr. Palmer limped back to the pits without his front wing and retired.
Ferrari's German driver Sebastian Vettel, who came home third, steers his car during the Italian Formula One Grand Prix
Felipe Nasr of Sauber (right) collides with Renault driver Jolyon Palmer (left) during the second lap of this entertaining race
Nasr's rear right wheel was damaged and he was forced to into the pit-lane after colliding with British driver Palmer
Nasr damages his right rear wheel after a collision with Palmer (not pictured) and both drivers were forced to retire
Pascal Wehrlein of Manor was also forced to retire from the race in Monza after following orders from his team via the radio
The stewards blamed Nasr, handing the Brazilian a 10-second penalty that was meaningless given that he was also terminally in the pits. Palmer was unimpressed. 'You see better racing in GP2,' he said.
Jenson Button, who announced this weekend that he would be semi-retiring from Formula One, seemed to be enjoying his time out on the fast Monza track. He jinked up from 14th to 12th, including a neat passing move on his McLaren team-mate Fernando Alonso at the first chicane.
Button, 36, will be spending next year as a McLaren ambassador and development/reserve driver, with a possibility to return to racing the following year.
He says he needs a break, but he was pretty frisky on Sunday.
Fernando Alonso struggled to a 14th place finish for McLaren but picked up the fastest lap after pitting for a late tyre change
Grid girls look on prior to the start of the Italian Grand Prix - the final European race of the 2016 Formula One season
A grid girl waits for the drivers' parade before the start of the Italian Grand Prix which held the 14th round of the campaign
Jenson Button (left) and Felipe Massa pose for a selfie before the race with both drivers set to depart F1 at the end of the year