No, they won the National League in 1998. They won their division title three other times.
A quick primer on American sports, since it seems to be causing so much confusion. The major American sports leagues (not including MLS) are broken into two halves (based on geography for hockey and basketball and based on historical reasons for the NFL and baseball), and then those halves are further subdivided into divisions. Confusingly, the halves in baseball are called the American League and the National League. The team that finishes first during the season in each division (plus some other runners up based on records, sort of like how third place teams in the Euros would move on to knockouts) goes to a postseason tournament against other teams from their half of the league. The winner of each half of the league goes on to a final against the winner from the other half. The Padres specifically won their division four times during Moores' ownership, and lost in the first round of the postseason three of those times. The fourth time, they won the first two rounds of the tournament (making them the winners of the National League), but lost in the overall final (to the winner of the American League).