* Verstappen wins chaotic Imola race
* Hamilton finishes second and stays top overall
* Seven-times champion takes bonus point for fastest lap
* Norris third for McLaren
* Perez goes from front row to 12th
(Adds penalties for Stroll and Raikkonen)
By Alan Baldwin
April 18 (Reuters) - Red Bull's Max Verstappen won a chaotic and crash-halted Emilia Romagna Grand Prix at Imola on Sunday with Lewis Hamilton second for Mercedes and staying ahead in the championship by a single point.
The win, by a commanding 22 seconds at the chequered flag of the season's second race, was the 11th of the Dutch youngster's career.
"It was very challenging out there, especially in the beginning to stay on track to be honest, it was very slippery," Verstappen said of an afternoon that started with most drivers on intermediate tyres but some on full wets.
Hamilton, winner of the Bahrain season-opener, took a crucial bonus point for fastest lap on a rollercoaster afternoon for the seven-times world champion, whose race was almost wrecked by a rare mistake.
The Briton started on pole, his 99th, but dropped from second to ninth after skidding into the gravel and nudging the barriers at Tosa with his car at a standstill and a retirement looming.
He kept the engine running, reversed back out and returned to the pits, a lap behind, for a new front wing.
A huge collision between team mate Valtteri Bottas and Mercedes-contracted Williams (NYSE:WMB) driver George Russell on lap 32 of the 63 threw him a lifeline by bringing out red flags with debris strewn across the track.
The drivers blamed each other, with Russell asking the Finn whether he had wanted to kill them both.
With the field closed up again, Hamilton fought his way back to the podium with a stirring recovery drive and passed McLaren's third-placed Lando Norris with two laps to go.
"On my side it was not the greatest days, it's the first time I've made a mistake in a long time," said Hamilton.
GREAT START
Norris's podium completed an excellent day's work for a driver whose deleted best lap in qualifying would have seen him start third rather than seventh.
Hamilton now has 44 points to Verstappen's 43, with Norris on 27. Mercedes stayed top of the constructors' standings with 60 points to Red Bull's 53.
Verstappen seized the lead into turn two on the opening lap, forcing his way through with a great start from third on the grid but making contact with the Mercedes as he went.
"I don't know if I've got damage, he pushed me right wide in turn one," exclaimed Hamilton.
There had been drama already before the start, with Sebastian Vettel starting from the pitlane after his Aston Martin's brakes overheated on the way to the grid and Alpine's Fernando Alonso spinning off.
There was more mayhem to come, with Canadian Nicholas Latifi smashing his Williams into the barriers on the opening lap after contact with Nikita Mazepin's Haas, bringing out the safety car.
Mick Schumacher, son of Ferrari (NYSE:RACE) great Michael, hit the wall at the pit lane exit and had to continue lapping without a front wing on his Haas due to the pit lane being closed to clear debris.
Verstappen's Mexican team mate Sergio Perez, who started on the front row for the first time, failed to score after a torrid afternoon.
He collected a 10-second time penalty for overtaking while the safety car was deployed after he skidded off and then retook the positions lost, but was up to fourth at the time of the stoppage.
The prospect of a podium then disappeared with another error, dropping him from fourth to 14th before he finally finished 12th.
Ferrari's Charles Leclerc did take fourth at the Italian team's home circuit and Spanish team mate Carlos Sainz was fifth, with McLaren's Daniel Ricciardo sixth after earlier letting Norris through.
Canadian Lance Stroll finished seventh for Aston Martin, but was then demoted to eighth post-race for leaving the track and gaining an advantage, with AlphaTauri's Pierre Gasly moving up a place.
Kimi Raikkonen, ninth at the flag for Alfa Romeo, was demoted out of the points after being handed a 30-second penalty for a rolling start infringement.
That lifted Frenchman Esteban Ocon up to ninth for Alpine with team mate Fernando Alonso 10th for the first point of his comeback after two years away.