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However , costly first-lap retirements in Belgium and Japan allowed his rivals to catch up , and defending World Champion Sebastian Vettel — like Alonso , a two-time title winner — took the lead in the sixteenth race of the season .
 person: Sebastian Vettel; person: Alonso
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: Sebastian Vettel; person: Alonso