The English Premiership strugglers were sent sprawling by a double sucker punch just before half-time, Matias Delgado netting a 43rd-minute strike before David Degen doubled the tally two minutes later at St. Jakob Park.

Boro' had coped with everything Basel had thrown at them for most of the first half and looked set to reach the interval with the scores level.

But out of nowhere Delgado found a moment of inspiration to breach the Boro' defence. The Argentine cut in from the right and unleashed a powerful shot from 25 yards that kicked up off the rain-soaked turf to beat Mark Schwarzer.

Boro' had barely recovered from the disappointment of that goal before they were two down. Brazilian playmaker Eduardo played in Degen, who looked once before thundering his finish past Australian international Schwarzer.

The English side never recovered from that lightning double-whammy, and could have seen their hopes completely snuffed out had defender Chris Riggott not made a superb goal-line clearance midway through the second half.

Boro' substitute Ugo Ehiogu went close with a powerful late header but the English side's hopes of stealing a precious away goal was thwarted by Basel keeper Pascal Zuberbuhler.

A miserable night for Boro' also saw trouble in the stands, with police moving in to quell sporadic scuffling amongst the travelling support.

"We gave away two poor goals and it costs you at this level," said Riggott. "But we don't feel like we're out of it."

Elsewhere in the UEFA Cup Wednesday, German side Schalke 04 put one foot in the semifinals after recovering from 1-0 down to win 3-1 away to Bulgarian side Levski Sofia.

Levski had the Germans in trouble early on when Daniel Borimirov capitalised on some poor defending to put the home side ahead.

But the Bundesliga side took control of the tie with a second half goal blitz that will leave them firm favourites to progress.

Uruguayan Gustavo Varela levelled it on the night with a finish high into the net after a neat one-two with Levan Kobiashvili before Brazilian midfielder Lincoln fired the visitor into the lead on 69 minutes.

German international Gerald Asamoah left Schalke in control of the tie when he followed up Christian Poulsen's header, which hit the post, to drive in the rebound.

The win means Sofia must score three times in next week's second leg to have any chance of progressing.

In other matches, Rapid Bucharest were held to a 1-1 draw at home by rivals and 1986 European champions Steaua Bucharest at the Giulesti Stadium in the Romanian capital.

Spanish side Sevilla all but assured themselves of a place in the last four with a 4-1 home win over St Petersburg of Russia.