* Bottas pips Hamilton to pole at Imola
* Mercedes lock out front row
* Verstappen qualifies third for Red Bull
* Thirteenth pole in 13 races for Mercedes
* Champions can clinch seventh constructors' title in a row (Adds details)
By Alan Baldwin
Oct 31 (Reuters) - Valtteri Bottas took pole position for the Emilia Romagna Grand Prix at Imola on Saturday with Mercedes team mate and Formula One leader Lewis Hamilton lamenting a poor lap and qualifying second.
Red Bull's Max Verstappen was third fastest, after a power unit scare in the second phase sent mechanics scrambling to fix his car, with AlphaTauri's Pierre Gasly a stand-out fourth on the grid.
Mercedes need only a fourth-place finish in Sunday's race, and maybe not even that, to secure a record seventh successive constructors' world championship.
The pole, with a time of one minute 13.609 seconds, was a 13th in 13 races for the champions and fourth for Bottas in 2020.
Sunday's race will be the first grand prix at Imola since 2006, with the track returning to flesh out a calendar ravaged by the COVID-19 pandemic, and the third in Italy this season.
"This track, when you push flat out, it's beautiful. I knew I had to improve in the last lap and I found those small gains that were needed," said Bottas, whose second flying lap was 0.097 quicker than Hamilton's.
"It's a great feeling when you get those.
"It's going to be a good fight. It's one of the longest runs in the calendar into Turn One so no doubt Lewis and Max will be chasing me, but it's a good place to start and hopefully the pace is good."
Hamilton leads Bottas by 77 points, having won eight times so far this season.
POOR LAP
The 35-year-old, who celebrated a record 92nd win at the previous race in Portugal, is closing on a record-equalling seventh drivers' title although he will have to wait at least until Turkey in two weeks' time for a chance to seal it.
"Valtteri did a great job. It was a pretty...poor lap from myself. These things happen, you can't always get it perfect," said Hamilton, who had been quickest after the first flying laps in phase three and also in practice. Emilia Romagna Grand Prix has been condensed into two days, without Friday practice and drivers having to get to grips with it quickly on Saturday.
Hamilton predicted a "pretty boring race" on Sunday with overtaking difficult.
"You can overtake on this long straight but it's quite narrow, and you can't follow. Once you get into Turn One, it's a train from there, there's no single place to overtake anywhere else," he said.
Australian Daniel Ricciardo qualified fifth for Renault (PA:RENA) with Verstappen's Thai team mate Alexander Albon sixth after having laps deleted throughout the three-part session for exceeding track limits.
"That was the best lap I've done so far this year," commented Ricciardo.
Ferrari (NYSE:RACE)'s Charles Leclerc will be seventh on the grid at a circuit named after team founder Enzo and son Dino, with four- times world champion team mate Sebastian Vettel only 14th.
The German lines up behind the Williams (NYSE:WMB) of George Russell, 13th, for the second race in a row.
AlphaTauri's Daniil Kvyat, whose place at the team is under threat for 2021, qualified eighth with McLaren's Lando Norris and Carlos Sainz ninth and 10th.
Alfa Romeo's Kimi Raikkonen, the oldest driver on the grid and only one with previous Formula One race experience at Imola, qualified 18th.