Zanardi had won an Italian Touring Car Championship round earlier this season, but this is his first victory in a world class event since he won the Champ Car race at Surfer's Paradise in October 1998.
The victory was also his first podium finish since he returned to racing in the series in 2004, after loosing both of his legs in his 2001 Champ Car accident, also in Germany. The Italian races in the series in a special adapted BMW 320i with hand controls.
Zanardi led every lap of the race but had to withstand severe pressure from fellow BMW drivers Jorg Muller and Andy Priaulx to become the eighth different winner in 14 races this season.
Muller challenged pole-sitter Zanardi mid-distance, even pulling up alongside him on the start/finish straight. However, he dropped back again and Zanardi appeared to have the race under control. On the penultimate lap Muller and Priaulx caught back up with Zanardi as the Italian continually locked his tyres on the final laps.
Muller attempted to pass on the penultimate corner when Zanardi made a small mistake, but the German ended up running wide off track as the Italian defended the position. Priaulx slipped through to take second but finished 0.232 seconds behind Zanardi. Muller scrambled across the line in third.
"It is difficult to find the right words," an emotional Zanardi said after the race. "I had such a nice career and whenever a driver comes to an end of their career the young people think that he should retire. But because people felt pity for me, that sentiment was not as strong about me. I had those thoughts too but I'm so glad my day finally came."
Zanardi revealed he believed that it was Jorg Muller's BMW teammate Dirk Muller behind him, who was carrying maximum success ballast this weekend.
"Jorg is a great driver and he is the one who is always driving to make the move," Zanardi added. "I thought it was Dirk behind me, who had more ballast, so I thought I had the advantage. My team were great in building me a car after I ruined the last one in Spa.
"We've finally found a set-up that works for my driving. This is one of the better moments, and I'm very focused. On the slowing down lap I was already thinking about the next race in Turkey and what we found out in the set-up. But I'm old enough to tell my mind to enjoy the experience tonight."
Zanardi also evoked memories of his Champ Car days, by completing donuts on the main straights after the chequered flag.
Priaulx's second place, combined with his win in the first race, moved him to within one point of Championship leader Dirk Muller, who finished sixth.
"My Championship chances are second to Alex's result today," Priaulx said. "He drove so well with no mistakes."
Muller was not upset about the final lap incident and losing second place on the final corner. He said: "I'm happy just to be part of the most historic race in the WTCC, seeing Alex win, and happy with my third position, to be honest."
The new SEAT Leon scored an impressive result on its debut weekend with fourth place for Jordi Gene ahead of Alfa Romeo's Augusto Farfus Jr.
Pos Driver Car Time
1. Alessandro Zanardi BMW 320i 21:59.901
2. Andy Priaulx BMW 320i + 0.232
3. Jorg Muller BMW 320i + 0.524
4. Jordi Gene SEAT Leon + 1.527
5. Augusto Farfus Jr. Alfa Romeo 156 + 2.290
6. Dirk Muller BMW 320i + 8.472
7. Rickard Rydell SEAT Toledo Cupra + 10.898
8. Alain Menu Chevrolet Lacetti + 11.022
9. Antonio Garcia BMW 320i + 11.397
10. Michael Funke Ford Focus + 11.788
11. Nicola Larini Chevrolet Lacetti + 12.978
12. Robert Huff Chevrolet Lacetti + 17.015
13. Tom Coronel SEAT Toledo Cupra + 18.034
14. Gabriele Tarquini Alfa Romeo 156 + 18.676
15. Stephane Ortelli SEAT Toledo Cupra + 21.590
16. Giuseppe Ciro BMW 320i + 23.322
17. Carl Rosenblad BMW 320i + 28.077
18. Adriano De Micheli Honda Accord Euro R + 52.495
19. Stefano D'aste BMW 320i + 53.681
20. Thomas Klenke Ford Focus + 1 Lap
21. Marc Hennerici BMW 320i + 1 Lap
22. Sascha Ploderl Ford Focus ST170 + 3 Laps
Driver Car On Lap
James Thompson Alfa Romeo 156 3
Valle Makela SEAT Toledo Cupra 2
Fabrizio Giovanardi Alfa Romeo 156 1
Peter Terting SEAT Toledo Cupra 1
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