The No.6-seeded Errani came out very strong, winning the first two games of the match at love, and after an hour and 21 minutes she broke serve one last time to complete a 63 61 victory over Larsson.
"The score was 63 61 in the end, but for sure it wasn't that easy a match," Errani said. "Many of the points were very long and she's a very strong player. It was a much tougher match than the score."
And there was something else about the win that was more draining than some of Errani's other wins.
"It's very dry out there - it's very difficult to play like that," she said. "Your mouth gets so dry - you want to drink every point but you can't. It's very difficult, so I'm very happy I could make it through."
"For sure I'm very happy about that," Errani said of the statistic. "I like competition much better than practice, so I play a lot of tournaments and a lot of matches - I really enjoy it. For the moment I'm doing well. Right now I'm very happy to still be in this tournament and I hope to keep going here."
The result was also a nice pick-me-up after she and Roberta Vinci, the No.1 doubles team in the world and the No.1 seeds at Indian Wells, were upset on Saturday, losing in straight sets to Hsieh Su-Wei and Peng Shuai. "We didn't play that well - the conditions are tough for us here - but they played a really good match," Errani said. "They played unbelievable and aggressive all the time, so it was really tough overall. But for sure we're okay. Sometimes your opponents play too well - it can happen.
"We will try again in Miami, for sure - we want to play again as soon as possible!"
"I know them both quite well but for sure I'll watch the match, maybe if it's on TV," she said.
Errani leads Bartoli in their head-to-head, 2-1, losing their first meeting back in 2007 but winning their last two meetings, both in 2012; Kuznetsova leads Errani in their head-to-head, 5-1, though there is good news for the Italian - her one win came in their last meeting, at the French last year.
Bartoli ended up winning that late night match over Kuznetsova in straights, 64 63.