Stevie Williams scored the biggest win of his career on Sunday when he won a five-rider sprint to take out the summit finish at Mt Lofty in the Adelaide Hills.

Tied for the overall lead in the Santos Tour thanks to his second placing at the iconic Willunga Hill climb on Saturday, the 27-year-old Israel-Premier Tech rider made sure of the title with his storming win on the final stage.

Williams' team director Daryl Impey, who won the Tour twice, called him Stevie Wonder on Saturday and he lived up to the moniker.

There was a strong Australian flavour to Williams' triumph, with Simon Clarke his team's road captain for the Tour and Nick Schultz also in their line-up.

Williams paid rich tribute to his team, saying they were "nailed-on" to do something in Adelaide.

It is a significant boost for Israel-Premier Tech after being relegated from the WorldTour at the end of the 2022 season.

Williams also spoke of the importance of the win to him.

"It's not so much a relief, but cycling's funny, because they (wins) don't come around so often," he said.

"Once you get a victory like this, you have to make sure you enjoy it and take it in.

"But for me to win a WorldTour GC (general classification, or overall) at this point of the season, it's really important for my development."

Mexican Isaac del Toro (UAE Premier Tech), the 20-year-old revelation of this week's Tour, attacked inside the last kilometre on Sunday.

But Williams had the last charge and he finished ahead of Ecuador's Jhonatan Narvaez (Ineos Grenadiers), with del Toro third.

Narvaez finished second overall at nine seconds and del Toro was third at 11 seconds.

Williams' career has been stalled by injury and he noted this is the first time he had begun a season with such a solid preparation.

"It's nice to actually start a season well for once," Williams said.

He was ill on the flight to Australia, but Williams arrived more than a week out and his third place on stage two showcased his form ahead of the weekend's key climbing stages.

He saw off the week's young movement, with 21-year-old Scot Oscar Onley (dsm) dropping to fourth overall after starting the final stage as the co-leader of the Tour.

Williams calls himself a puncheur - a rider who excels on short, sharp climbs.

It is unclear yet whether he will target three-week Grand Tours and perhaps emulate Geraint Thomas, who in 2018 became the first Welshman to win the Tour de France.

"I don't think we can pigeon-hole him into something yet; let him evolve," Impey said.

Typical of the week's defensive racing, the contenders did not animate Sunday's stage until the final 3km climb.

Top Australian team Jayco AlUla had a barren week, with no stage wins and their British star Simon Yates finishing sixth overall.

The top-placed Australian was Damien Howson (national team), who was ninth, while Olympic track medallist Sam Welsford provided the local highlight of the Tour with his three stage wins in the sprint finishes.

Luke Burns (national team) also took out the mountain classification.

Sunday's sixth and final stage was 128.2km from suburban Unley, through the Hills.

Australian Associated Press