The Braves were able to salvage the finale of the three-game series, as Hanson got through his start and illness every bit as well as Josh Beckett had done for the Red Sox on Friday night.
"I thought he was good," Francona said. "If he was sick, I don't really want to see him when he's not sick."
Over six shutout innings, the 22-year-old Hanson allowed just two hits -- both singles. In five Major League starts, Hanson is now 4-0 with a 2.48 ERA.
The righty was such a question mark that Braves manager Bobby Cox actually had Medlen warm up before the game as well, just in case.
"Last night when we left here, the medical staff said it would be a miracle for him to start," Cox said. "He had a high fever when he left and felt horrible. They hydrated him really well, and he said he was good to go."
Hanson's performance was enough to spoil another solid start by Brad Penny, whose only blemishes were solo homers by Chipper Jones and Garret Anderson.
Over six innings, Penny scattered six hits and just the two runs, marking the seventh time in his past eight starts he's allowed three earned runs or less.
"We lost the game, so there's no satisfaction in pitching good if you lose," said Penny, who fell to 6-3. "It's nice to be healthy again."
The loss marked the end of Interleague Play for the Sox, who finished 11-7 against National League foes. This was the third straight road Interleague series during which Boston won the first two games but couldn't close out the sweep.
"As long as we keep winning series, that's a good thing," second baseman Dustin Pedroia said. "You want to sweep teams, but it's tough. Everyone's got good players, and it's tough to sweep a Major League-caliber team."
The Red Sox, as they usually do, created chances even in defeat.
Boston's most promising rally of the day came right after Hanson's exit. With one out in the seventh, Jason Varitek hit a hard grounder that went off the glove of second baseman Kelly Johnson and into right. Noticing how much the ball slowed down on the way to right fielder Jeff Francoeur, Varitek alertly hustled into second for a double. Jacoby Ellsbury was then given a gift, reaching on an error by Johnson to set up runners at the corners and just one out.
But Braves reliever Peter Moylan made just the pitch he needed, getting a 4-3 double play off the bat of Nick Green to quash the rally.
"It seems like every time we got something going, we were one big hit away," Pedroia said. "We hit some balls good and just no luck. We had a chance there at the end. That's all we could ask for."
In the ninth, seeking the proverbial bloop and a blast, the Red Sox got the former when Kevin Youkilis led off with a single to left-center field. With one out, it looked as if David Ortiz had then hit a game-ending double play to first. But Youkilis deftly created a rundown and got back to first safely after Ortiz had been retired.
Varitek wound up singling home Youkilis, but Ellsbury struck out against Braves closer Mike Gonzalez to end the game.
"We've got a lot of fight in our team, and we're going to battle it out until the last out," Youkilis said. "You're not fighting time, you're fighting the last out, so we're going to scrap away and do what we've got to do. We came up short today, but we won the series. You have to look at it that way. You can't be upset about it. You want to win all the games, but winning the series is most important."
"We weren't able to win today, but we've won those games before and we'll win them again," Francona said.
There was some brief early concern about Penny two batters into the bottom of the first, when he tweaked his thumb after making a pitch to Johnson.
"It kind of popped out of the joint for a second, but it was nothing," Penny said. "I just needed a second to let it come back. I was just gripping the ball a little too tight. It's happened to me four or five times in my career.
The righty probably felt more pain when Jones got his 75-mph curveball and lofted it just over the fence in left for a homer with two outs in the first.
The Red Sox didn't get a hit off Hanson until the fourth, when Jason Bay and Ortiz struck back-to-back two out singles. Varitek walked to load the bases, but Hanson got Ellsbury on a grounder to second to end that threat.
Making the lost opportunity more painful, Anderson led off the bottom of the fourth with a solo homer to right to make it 2-0.
All-in-all, though, it was an effort the Red Sox will gladly take every time out from Penny.
"He's throwing the ball great," Pedroia said. "He's a power pitcher, and he's been locating and his offspeed has been better and better. We're glad to have him."