LONDON - Red Bull were able to celebrate their second Formula One title double in a row in Japan at the weekend, even if Max Verstappen must wait until October to be confirmed as a triple champion.

The team's sixth constructor's championship in their 19 year existence was secured at Suzuka, despite Mexican Sergio Perez failing to finish, after Verstappen dominated from pole position.

The fact that Perez is now the only driver who can mathematically beat Verstappen to the title meant Red Bull had done the double for a sixth time.

"We can't lose it now," said team boss Christian Horner. "Only a Red Bull driver can win the championship which is a great way to go into the next few races."

Realistically, Perez has no chance and any sense of suspense disappeared long ago.

Verstappen, who turns 26 on Saturday, will not need to do even one more lap if Perez, who started the campaign strongly with two wins in four races, continues his current form.

The 33-year-old Mexican had a nightmare on Sunday with collisions, penalties, a retirement and subsequent un-retirement in a race that ended Red Bull's 100% finishing record for the season.

"It was a shocker of a race for him," said Horner. "He got off to a bad start where he sort of got concertinaed on the run down to turn one and picked up some front wing damage.

"Then we needed to change the front wing and he overtook Fernando (Alonso) on the way in to the pit lane, then picked up a penalty and then he went out and dive-bombed one of the Haases."

Perez retired but returned towards the end of the race to serve a penalty and avoid it being carried over to Qatar as a grid drop.

Even if he suddenly achieves perfection he is now too far behind for it to make a difference against the winner of 13 of 16 races.

Verstappen is 177 points clear with 180 available to be won from the remaining six rounds -- 25 per grand prix win plus a total of six for fastest laps and three Saturday sprints paying out a maximum eight additional points to the winner of each.

After Qatar, the first of the remaining sprint weekends, there will be only 146 available.

That means Verstappen needs only three points to be champion even if the Mexican bags a maximum score at Lusail.

Perez won the Saturday sprint and Sunday race in Azerbaijan this year for a haul of 33 points, but Verstappen took 24 points from the same weekend and won the subsequent sprint races in Austria and Belgium.

It has been 36 races since Verstappen last came away from a weekend without scoring at least three points. Perez, on the other hand, has made it to the podium in only half the races this season.

If Verstappen clinches the title in the Saturday sprint in Qatar it would be the first time since the 1983 South African Grand Prix that the championship has not been won on a Sunday.

(Reporting by Alan Baldwin, editing by Ken Ferris)