Lula pulled off a historic comeback win over Flávio Bolsonaro in Brazil's runoff, rattling markets and setting up a tense next few years.

• Lula won narrowly after trailing badly in polls, with huge last-minute turnout from his base reversing the first-round result.
• Brazilian stocks dropped sharply, giving back a big chunk of the gains investors had piled on when Bolsonaro looked like the likely winner.
• Bolsonaro is disputing the result and may not concede, even though both sides had asked for the same voting extension he's now complaining about.
• Bolsonaro's allies made major gains in Congress and nearly control the Senate, meaning Lula will have a hard time governing.
• A corruption scandal touching Brazil's Supreme Court has weakened its credibility, and both candidates had promised court reform — raising the risk of political turmoil ahead.

Outlook: Expect a rocky term for Lula, with a hostile Congress, market jitters, and possible moves toward judicial reform or even impeachment fights down the road.