Two goals by Diego and a Claudio Pizarro strike guided Werder Bremen through to the UEFA Cup semi-finals after Udinese Calcio had wiped out their 3-1 first-leg deficit before half-time.
Despite Diego cancelling out Gokhan Inler's 15th-minute strike, the momentum was with Udinese at the break as Fabio Quagiarella struck twice. But Diego's second of the match, on the hour mark, swung the tie back in favour of the Bundesliga side, who added to their tally through Pizarro on 73 minutes moments after Diego had missed a penalty for his hat-trick.
Thunderstorms were predicted ahead of the match, but though the rain stayed away until half-time, other pyrotechnics were thick on the ground. After Werder had gone close when Naldo's header was deflected wide by team-mate Petri Pasanen, Inler gave his side hope with a lightning strike on the quarter-hour. Receiving a ball from Kwadwo Asamoah, Inler cut inside from the left and dispatched an unstoppable 30-metre shot into the top corner.
Udinese's tails were up, now just a goal from taking the initiative in the tie, but they were almost pegged back moments after taking the lead as Hugo Almeida pounced on Clemens Fritz's right-wing cross, and skewed it wide. The game had opened up and was swinging from end to end when the equaliser arrived on 28 minutes. Cristián Zapata dallied and Diego, so unsure of playing in the build-up to the match, took the loose ball in a flash before turning inside and shooting past Samir Handanovič.
It did not take long for the Zebrette to restore their lead on the night – two minutes in fact – a long ball from Giovanni Pasquale sending the quicksilver Quagliarella clear to lob Tim Wiese for his seventh UEFA Cup goal. Seven soon became eight, on 38 minutes, but not before Almeida shot over after a delightful through ball from Mesut Özil. Again Bremen were made to pay as from the ensuing counterattack Felipe found Inler, whose deft touch gave Quagliarella enough time to swivel and shoot low into the net.
There was little change after the interval, the livewire Quagliarella coming centimetres short of a hat-trick as he turned another shot wide. Suddenly, though, Bremen were in charge again as Claudio Pizarro picked out Almeida in space, the striker lashed an angled shot against the bar and Diego headed over the line before Handanovič could clear.
Udinese now needed two more goals and after Felipe had fired across goal, Asamoah came closer to getting one when he hit the left post. Diego earned the chance to kill the tie from the penalty spot with 17 minutes left as he was fouled by Maurizio Domizzi, and though Handanovič guessed right to deny the Brazilian, from the subsequent corner Pizarro turned Per Mertesacker's header into the roof of the net to ensure a semi-final meeting with Hamburger SV on 30 April and 7 May.