MOSCOW — In a blow to Western efforts to tug former Soviet lands out of Moscow’s orbit, a strong supporter of President Vladimir V. Putin of Russia finished far ahead of pro-Western candidates in a presidential election on Sunday in Moldova.

But the Putin supporter, the Socialist Party leader Igor Dodon, fell just short of the majority needed to secure outright victory and faces a runoff election. With about 99.5 percent of the results in, Mr. Dodon had 48.5 percent of the vote, according to Reuters.

Mr. Dodon, whose campaign for the presidency featured photographs of his meetings with Mr. Putin, finished in front of eight rivals, with Maia Sandu, a former World Bank official, winning 38.2 percent to place second.