Earlier quoted context omitted.
The Nazi party was certainly the winner or the election in July 1932, where it became the largest party in the parliament. In March 1933 elections it became even larger, with 44% more than twice the size of the second largest party, the SPD. It just never had an absolute majority - the parliamentary act which effectively gave the party dictatorial powers was supported by the conservative and center parties.
I guess we can argue over what it means for a political party to win, but the Nazi party were never able to gain the support of the majority of the German people.
The Nazi party itself did not have an absolute majority at any point, but they gained power by getting support from a majority in parliament, representing a majority of the voters. The power was achieved legitimately, but then it was used to dismantle the democratic system.