Lewis Hamilton celebrates with his father Anthony Hamilton following his second place finish.
Alonso, who left Renault for Mercedes-powered McLaren at the end of last season after winning the last two titles, was full of praise for his "perfect" new team.
"To win a formula one grand prix with two different teams is something special...a dream come true and part of history," Alonso told a news conference.
"We knew our chance was to overtake the Ferraris at the start, and to see Lewis in second was even better."
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