After seven days of vote counting, San Jose City Councilmember Matt Mahan widened his lead slightly in the race for mayor of San Jose, with a 4,256-vote margin, an increase of 625 votes, after three straight days of losing ground to Santa Clara County Supervisor Cindy Chavez, according to unofficial results reported Monday.

As of 4:57pm Monday, Mahan's tally in the ballot-counting marathon stood at 1.98 percentage points ahead of Chavez.

The Monday ballot count in the San Jose mayoral election showed Mahan with 109,477 votes,  a gain of more than 6,000 votes from Sunday's count and 50.99% of the total, while Chavez had 105,221 votes, or 49.11% of the total.

Chavez still has an uphill battle, with her window of victory closing as Mahan's lead holds. She would have to increase her winning percentage of the approximately 57,000 uncounted ballots to 55%, in order to wipe out his lead.

Because the county does not estimate how many city vote-by-mail and provisional ballots are uncounted, it remained difficult Monday to determine when a candidate could declare victory.

Applying the Nov. 14 countywide estimated 79% ballot count to city of San Jose returns would mean there could be 57,000 votes outstanding; but that number could be off by thousands in either direction because the elections office doesn’t estimate which precincts are the source of the uncounted ballots.

Elections officials estimated that more than 124,000 ballots countywide remain to be counted. Last week they had said they would announce results every other day this week, instead of the daily reporting in the week after the Nov. 8 vote.

The office reported at 5:01pm today that 467,999 were counted Monday, just over 30,000 more than Sunday's countwide total, leaving 21% to count.

In the years since mail-in ballots became the predominant form of voting locally, the results from precinct votes have been accurate predictors of eventual outcomes. Mahan has been in the lead since the Nov. 8 vote.