World champion Max Verstappen rekindled his title defence and acclaimed his resurgent Red Bull team on Sunday after he led Sergio Perez home in a dominant one-two triumph in Ferrari's backyard at the Emilia Romagna Grand Prix.

In a rain-affected race, the 24-year-old Dutchman came home 16.5 seconds ahead of his Red Bull team-mate as Charles Leclerc and Ferrari endured a disappointing day in front of passionate home support at the Autodromo Enzo e Dino Ferrari.

Leclerc, who started second on the grid, finished sixth after making a poor start and spinning in the closing laps while running third, allowing Lando Norris to take third for McLaren.

After Saudi Arabia, it was Verstappen's second win this season which has also included two retirements, and the 22nd win of his career.

He reeled off a 'grand slam' weekend with pole position, victory and fastest lap as well as victory in Saturday's sprint race.

He moved up to second in the title race behind Leclerc, reducing his deficit from 45 points to 27 to set up the prospect of an intense duel this year between them and their teams.

"It's always tough to achieve something like that, but already yesterday and the day before, we were on it," said Verstappen.

"And it was looking like a strong weekend. You never know with the weather how competitive you are going to be, but I think we did very well and this one-two is very deserved.

"The start was very important, but afterwards, judging the conditions and when to swap to the slick tyres -- because in the lead you have to always dictate the pace."

Perez said he was delighted to bring smiles to the Red Bull team.

"It was really intense," he said. "The most important thing today was not to make mistakes because with these conditions it was so tricky. To get a one-two, out there, is a great result for the team.

- 'Undriveable' Mercedes -
"I am very pleased to see everyone in my team smiling today and I am happy for Max."

Norris said: "An amazing race! An amazing weekend.

"I'm happy. The team deserves it. It was a mixture of tricky conditions, but we've been able to capitalise on that -- I love these conditions, so always do quite well."

George Russell produced a stirring drive for Mercedes to come home fourth after starting 11th, fending off Valtteri Bottas's Alfa Romeo at the finish, while team-mate seven-time champion Lewis Hamilton finished a distant 13th.

Mercedes team chief Toto Wolff apologised to a disappointed Hamilton on team radio after the race.

"I am sorry for what you had to drive today," said Wolff.

"I know it was undriveable – this was a terrible race."

"No worries, Toto," Hamilton responded. "Just keep working hard."

"We will come out of this," said Wolff, who added later that Mercedes "are not good enough for a world champion – and just need to fix the car."

AlphaTauri's Yuki Tsunoda finished seventh ahead of four-time champion Sebastian Vettel in an Aston Martin, Kevin Magnussen of Haas and Lance Stroll of Aston Martin.

Verstappen surged into the lead from pole position.

Leclerc, starting second, was passed by the Dutchman, Perez and Norris before Daniel Ricciardo in a McLaren tangled with Sainz at the first chicane.

It was a second consecutive early exit for Sainz after his misery in Melbourne.

Hamilton, who had been reluctant to pit, was impeded by Estaban Ocon's Alpine, but avoided a collision while Perez, who stopped on lap 19, managed to retain second place ahead of a charging Leclerc.

Ocon was given a five seconds penalty for his unsafe release.

By half-distance, Verstappen was cruising with a 10-second cushion ahead of Perez and Leclerc, frustrated in third.

On lap 41 came Hamilton's most humbling moment when he was lapped by Verstappen as he battled for 13th with Pierre Gasly's Alpha Tauri.

Leclerc pitted on lap 50 for softs, dropping to fourth behind Norris. Perez followed on 51, as Leclerc passed the McLaren and Verstappen one lap later, retaining a 13-second lead.

The Monegasque charged hard to pass Perez on lap 53, but spun off at Variante Alfa, damaging a front wing.

He pitted, re-joining eighth as Norris inherited third and Russell took fourth, resisting Bottas in the final laps.