In a one-sided first half, goals from Sebastian Prödl and Arnautovic set Bremen on their way and, though Sejad Salihovic pulled one back soon after the restart, the hosts had no response to the Austrian who proved Hoffenheim's worst enemy as he capped off a superb performance with his first ever Bundesliga hat-trick.
With the snow falling thick and fast at the Wirsol Rhein-Neckar Arena, both sides took time to get to grips with the slippery surface as rash challenges prevented the match from establishing an early rhythm. Salihovic fancied his chances with an early 35-yard free-kick that failed to find the target, but while Hoffenheim were breaking quickly, it was Bremen who were enjoying the better of the play. Clear sights of goal, however, were virtually non-existent in the opening quarter of an hour.
Unsurprisingly, it was Werder who took the lead as the hosts conceded from a set-piece for the 15th time this season when Prödl climbed above Joselu to loop his header over the stranded Koen Casteels. Persistent fouls continued to disrupt the flow, but it didn't stop Bremen extending their lead as Arnautovic played a one-two with Kevin de Bruyne to slice through Hoffenheim's back line before rolling the ball beyond Casteels on the half-hour mark.
The seriousness of the situation was only highlighted when Babbel made a double substitution after 36 minutes to protect Stephan Schröck and Sven Schipplock, who had both been booked. It had little effect on proceedings though, as de Bruyne and Nils Petersen both squandered golden opportunities one-on-one with Casteels, forcing Werder to settle for a two-goal lead at the break.
Having demonstrated next to no attacking threat in the opening 45 minutes, Hoffenheim struck back within five minutes of the restart with their first real chance of the encounter. The hosts scrapped to win possession on the right allowing Roberto Firmino to play in Salihovic, who made no mistake in slotting the ball beyond Sebastian Mielitz to hand the Sinsheim side a much-needed lifeline.
Arnautovic flashed an effort over in the hope of restoring Werder's earlier advantage, but 1899 had woken up after opening their account as they pressed higher up the pitch, forcing the visitors to make mistakes. The hosts were carving out their chances, but were lacking a clinical streak in front of goal as Mielitz bravely rushed off his line to deny Joselu, before the Spaniard's acrobatic attempt from Kevin Volland's cross flattered to deceive.
With Hoffenheim taking risks, Bremen once again assumed control and, shortly after, Casteels produced a superb reaction save to deny Theodor Gebre Selassie from close-range, Arnautovic stepped up to bag his brace by curling in an unstoppable free-kick from 20-yards. The Austrian was in fine fettle and soon completed his hat-trick, collecting Joseph Akpala's through ball, before turning Vincenzo Grifo inside out and finding the top corner to kill off the game, securing a convincing win for Werder.
Line-ups and statistics