despite missing the final three rounds of the championship to complete his education by graduating as an engineer from the Turku Technical Institute. In 1971, Giacomo Agostini was the reigning three-time 350cc world champion riding for MV Agusta however, Saarinen served notice by winning his first 350cc Grand Prix race in Czechoslovakia after Agostini's motorcycle had a mechanical failure. He then finished second to Agostini in the Finnish Grand Prix before winning the Nations Grand Prix in Italy. Saarinen competed in both 250cc and 350cc classes in 1971, finishing third in 250cc World Championship and second to Agostini in the 350cc class. He also showed his versatility at the Spanish Grand Prix by finishing second in the 50cc race aboard a Kreidler then winning the 250cc race on a Yamaha. Saarinen's success didn't go unnoticed as Yamaha contracted him to ride their 250cc and 350cc motorcycles for the 1972 season. The Yamaha factory gave him the second 250cc Yamaha TD-3 (YZ635) after Barry Sheene complained about its performance at the third round in Austria. Saarinen rewarded Yamaha's faith in him by winning the 250cc World Championship in a tight season-long battle with Renzo Pasolini and Rod Gould. He finished second in 350cc World Championship, giving defending champion Giacomo Agostini a strong challenge by winning three races, including a victory at the German Grand Prix held at the daunting Nürburgring race track, where Saarinen defeated Agostini for the first time in a head-to-head race. He also scored a double victory at the Czechoslovakian Grand Prix with victories in both the 250cc and 350cc classes. The threat from Saarinen's performance was so strong that the previously dominant MV Agusta factory was forced to produce a new 350cc motorcycle for Agostini. After the world championship season ended, Saarinen traveled to Great Britain where he won the Race of the Year invitational held at Mallory Park. At the end of the season, Saarinen negotiated with the Benelli factory about the possibility of riding 350cc and 500cc Benellis in the world championships. After a secret test ride at Modena, he rode Benellis to victories over Agostini in the 350cc and 500cc races at the Pesaro street circuit. The Yamaha factory reacted to the possibility of losing their star rider by signing Saarinen to a factory-backed sponsorship to compete on the newly developed YZR500 for the 1973 season. He would also defend his 250cc world championship