The 28-year-old New Zealand-born wing will definitely be occupying England minds as he lived up to his pre-match hype against an out-of-form Welsh side.
An eight-team event will feature Europe's leading six nations as well as Fiji and Georgia, who came in after Japan withdrew because of travel restrictions.
A thumping win for defending Grand Slam champions Wales over Italy, Ireland grinding out a victory over Scotland, and France pulling the punches in defeating England.
In-form Anton Lienert-Brown and Jack Goodhue got the nod for the defending champions in midfield, with coach Steve Hansen saying it had been a tough proposition to sort out his centre combination.
But Ireland's display was not akin to their 62-12 thrashing of Russia at the 2011 World Cup or indeed reigning champions New Zealand's 63-0 rout of Canada on Wednesday.
The 34-year-old fly-half missed Ireland's shock 19-12 defeat by hosts Japan in Shizuoka on Saturday, which threw Pool A wide open, with a knock he suffered in the opening 27-3 win over Scotland.
In a shock result that rivals their "miracle of Brighton" defeat of South Africa at the 2015 tournament, the Brave Blossoms took the lead through a Kenki Fukuoka try halfway through the second half and hung on desperately with a courageous defensive effort.
Ireland won 27-3 against Pool A rivals Scotland to open their World Cup campaign in convincing style in Yokohama on Sunday.
The tournament promises to be one of the most open in history, with at least five or six teams capable of preventing favourites New Zealand from winning an unprecedented third consecutive title.
Despite predicting a surprise win over world number one Ireland, the two octopuses anticipate Japan will lose their remaining three matches to Russia, Samoa and Scotland.
The Springboks have risen to the fourth position, All Blacks moving to second with Ireland occupying the top spot.
Ireland got into the game as favourites on the back of winning 11 of their 12 Tests last year including a historic home win over double world champions New Zealand.
Sexton received the prestigious Pat Marshall award at the club’s annual dinner following a remarkable 12 months that also saw him crowned world player of the year.
Joe Schmidt has been touted as a successor to Steve Hansen as coach of his native New Zealand when both of their contracts expire after the 2019 tournament.
The 33-year-old Leinster fly-half is only the second Irish player to win the award after hooker Keith Wood in 2001.
Midfield back Ryan Crotty was the only change to the All Blacks side that started against England as New Zealand coach Steve Hansen named his strongest available team for their clash against Ireland on Saturday.
David Pocock, who sat out the 2017 season on a sabbatical, was a constant menace at the breakdown as the Irish fell to the first defeat in 13 Tests.
Regular props Tendai Mtawarira and Coenie Oosthuizen return to the front row.
