Armstrong finished strongly to move up a place in the standings
Lance Armstrong got caught up in a crash in a rain-affected second stage of the Tour of California, but managed to climb the standings to fourth.
The seven-time Tour de France winner suffered the fall after a motorbike carrying a photographer crashed directly in front of him.
But Armstrong managed to make up the lost ground to move up from fifth, while Thomas Peterson won the stage.
Defending champion Levi Leipheimer moved into the overall lead.
Leipheimer, Armstrong's team-mate with Astana, finished a close second behind Peterson, who won the 186.6km stage in five hours, six minutes and 20 seconds.
Australia's Michael Rogers moved into second overall, 24 seconds behind Leipheimer, with a third-place stage finish, while David Zabriskie is a further four seconds back and Armstrong another two seconds adrift.
Leipheimer emerged from the chasing pack with around 20km to go, and with overnight race leader Francisco Mancebo fading on the final climb he was able to move to the top of the standings.
"The weather has been nasty the last couple of days and it really changes the race," said Leipheimer.
"I felt great, and I told [team-mate] Yaroslav Popovych 'I feel great, let's go'. I couldn't wait any longer. I had to go."
Armstrong crashed into the photographer about 120km into the stage but was able to make up the lost ground on a replacement bike.
It was more bad luck for the American, coming a day after he had his team-trial bike stolen.
"A motorcycle for the photographer from the race crashed right in front of me," said Armstrong.
"It was unfortunate, but it could have been worse. I don't feel too bad, my hip is a little banged up but overall it was a great day. Levi proved he is the best guy in the race hands down."
Floyd Landis, who was stripped of the title of the 2006 Tour de France after testing positive for testosterone, is 29th overall on his return to competition after a two-year doping ban.
The nine-day race continues on Tuesday with a 167.7km stage from San Jose to Modesto.
Armstrong's appearance in the Tour Down Under in Australia in January marked his first race since his final 2005 Tour de France triumph.
The Tour of California continues his build-up to a European campaign which is set to include the Giro d'Italia and the Tour de France.