SIR BOBBY Robson yesterday began Newcastle United's summer spending spree in spectacular style with an £8.4m swoop for Hugo Viana, the "golden boy'' of Portuguese football.

Robson returned to his former club Sporting Lisbon and beat off rival interest from Liverpool and Spanish side Celta Vigo, to land the 19-year-old midfielder.

The deal is a world record for a teenager and caps a remarkable rise for Viana, who United chairman Freddy Shepherd claims is "the best young player in the world at the moment''. Shepherd stayed up half the night to finalise negotiations in Lisbon before flying back to Tyneside with Viana, who yesterday agreed a five-year deal and underwent a medical.

He returns to Portugal this morning but will link up with his new teammates for the start of pre-season training next month.

Viana, who becomes Newcastle's third most expensive recruit - Alan Shearer cost £15m and Laurent Robert £9.5m - won an 11th-hour World Cup call-up in the wake of Sporting's Portuguese title triumph.

The playmaker destroyed England in the European Under-21 Championships last month and was then drafted into Portugal's senior squad after Maritimo's Daniel Kenedy failed a drugs test.

Viana didn't feature in his country's disastrous Far East campaign, but Shepherd said: "The general consensus is that he is the best young player in the world at the moment.

"We have signed Hugo for $12m and we are delighted to have him for the next five seasons.

"He's a very attack-minded, left-sided midfielder and I'm sure he will be a very good addition to the squad. He's just the player Bobby Robson wants to spearhead our Champions' League bid next season." Shepherd, who was accompanied by deputy chairman Douglas Hall, admitted to a few "scary moments" over the transfer after Celta Vigo also agreed a fee and Liverpool launched a late move.

He said: "Douglas Hall and I were determined to get our man and we kept the Sporting people up through the night.

"To tell the truth, we had a few scary moments. Sporting had already agreed a fee with Celta Vigo and then Liverpool actually moved in yesterday.''

Manager Robson made a personal trip to watch Viana in April in Portugal's friendly victory over Brazil, and then sent chief scout Charlie Woods to spy on him in the UEFA Under-21 Championships.

A scout from another Premiership club said: "Viana was the best player in the tournament and that's why he was called up for the World Cup finals. Newcastle have signed a gem."

Viana, who had an £8m buy-out clause in his contract, had also been linked with AC Milan in a swap deal involving Rui Costa.

With four full caps, Viana is seen as Portugal's long-term replacement for his hero Costa, who recently labelled him a "great footballer".

But the modest youngster insisted: "Who am I to take Rui Costa's place? We are different players."

Viana, full name Hugo Miguel Ferreira Viana, could face his former club in the Champions' League.

His arrival at Newcastle is further evidence of Robson's determination to build his side around youth - he paid Nottingham Forest £5m in February for 19-year-old midfielder Jermaine Jenas.

And it puts extra pressure on 32-year-old Welsh international Gary Speed, who holds the record for Premiership appearances.

Viana is already well known to Jenas and Newcastle teammate Shola Ameobi. Striker Ameobi played in England's 3-1 defeat by Portugual at the Under-21 Championships in Zurich, while Jenas was on the bench. Viana ran the game from a central midfield position and grabbed the third goal to kill off England's resurgence.

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