Toto Wolff hailed Lewis Hamilton's "surreal" record-breaking 92nd Formula One victory and joked it may now be too costly to tie him down to a new Mercedes contract.

The six-time world champion moved beyond Michael Schumacher's tally of wins with another masterful drive in Sunday's Portuguese Grand Prix at Portimao.

Hamilton crossed the line 25 seconds ahead of team-mate Valtteri Bottas, who he now leads by a mammoth 77 points, for his eighth triumph in 12 races this season to create more history in a remarkable career.

Mercedes team principal Wolff told Sky Sports: "Who would have have thought when we started this project in 2013... it's almost a surreal amount [of wins],

"It's his absolute passion and energy and everything he puts into the sport - and the talent and the ability. He's just standing out.

"This season he has ramped it up. It's a lot of learning, understanding the tyres and after the first couple of laps he was just sitting comfortably - then he just ramps it up even more."

Hamilton is into the final year of his Mercedes contract and has held off from holding formal talks over a new deal.

As the 35-year-old closes in on a record-equalling seventh title, Wolff admitted it will now likely take an even bigger sum to keep him in place.

"It's huge! We have to sell plenty of inventory," he said while laughing. "We'll have to sell the lease back of the buildings, just to come up with the money."