BARCELONA (REUTERS) - Rival team bosses Toto Wolff and Christian Horner said on Wednesday (Feb 23) that Formula One needed to turn the page on the controversies of the contentious 2021 title battle and especially the season-ending Abu Dhabi Grand Prix.

The year served up one of the closest and most riveting battles in Formula One history as Mercedes driver Lewis Hamilton and Red Bull's Max Verstappen engaged in a no-holds-barred battle of the generations that went all the way down to the last race in Abu Dhabi.

The intensifying fight between the two drivers led to several flashpoints over the course of the year, with the rivals even colliding three times.

But none was as controversial as the Yas Marina finale, in which a last-minute change to safety car rules by race director Michael Masi allowed Verstappen to seize the race lead and the title from Hamilton on the final lap.

"Look, 2021 has been well-documented," Red Bull boss Horner, who engaged in an equally intense off-track war of words with Mercedes rival Wolff, told a news conference on the opening day of the first pre-season test in Barcelona.

"I think that maybe we share a difference of opinion over Abu Dhabi but that's now done and dusted and all focus is very much now on 2022."

More than 108 million television viewers tuned in to watch the Abu Dhabi winner-takes-all showdown, with Hamilton and Verstappen going into the race level on points.

Debate over the manner in which the title was decided has rumbled on through the off-season, culminating in a sweeping change to the sport's refereeing process, including Masi's removal as race director, unveiled by the governing FIA last week.

Wolff, sitting alongside Horner, said it was time to move on.

"There's been so much talk about Abu Dhabi that it came to a point that it is really damaging for all of us stakeholders of Formula One. We've closed the chapter and moved on."

On his off-track feud with Horner, which included the pair reporting each others' teams and drivers to race stewards, questioning the legality of their cars, casting aspersions on stewards' impartiality and trading direct insults, Wolff said it was only to be expected.

"It got fierce at times and brutal but there's a lot at stake," said the Austrian.

"I don't know if I enjoy it but it's part of the job."