WASHINGTON -- When Austin Kearns stepped up to bat with two outs and two on in the bottom of the 10th inning at Nationals Park on Sunday, it wasn't a foregone conclusion that the contest would extend to an 11th inning, but that circumstance was certainly the most plausible.

Kearns, who was batting in the fourth slot as a defensive replacement in the ninth, went into the at-bat hitting .196. He had not driven in a run all month.

But in came a fastball from Padres reliever Greg Burke, out went a sharp line drive to the right-center field, and home came Nyjer Morgan from second base, giving the Nationals a 3-2 victory and Kearns the biggest hit of his season.

"Austin is just such a pro, and he gave us a professional at-bat," manager Jim Riggleman said. "He got a good pitch to hit and drove it. We use Austin as an example a lot of times about being a pro. He's in a tough situation, not getting to play as much as he normally has in his career, but he does his work every day, gets ready for those situations defensively, offensively, anything he can do to help the ballclub."

The game, a rubber match of a three-game series between the two teams with the worst records in baseball, probably should never have gotten to that point, but Riggleman said he was glad it did.

Nationals closer Mike MacDougal blew a save in the ninth inning when Padres rookie Kyle Blanks crushed a two-out home run to left field to tie the game at 2.

That erased what would have been an eighth win for John Lannan, who dazzled again after throwing a shutout against the Mets on Tuesday.

On Sunday, he hurled eight innings of five-hit, one-run ball, needing only 81 pitches. From the last out of the second inning to the first out of the sixth, Lannan retired 11 in a row (nine by groundout). Displaying his typical pinpoint control, he threw just seven balls in the first five innings.

"He's a guy who is so efficient that he looks better to hit than he is," Padres center fielder Will Venable said. "It's not riding [the ball] that hard, it's just funky enough. You get in trouble not giving him as much credit as he deserves."

Lannan gave up his lone run on a pair of doubles in the sixth. To that point, the Nationals could not crack San Diego starter Chad Gaudin, but Josh Willingham put the team on the board with a game-tying solo shot in the seventh.

With Lannan's spot due up to lead off the eighth inning, Riggleman pinch-hit Morgan for the pitcher.

Morgan didn't reach in that inning, but Willie Harris did with a one-out single. Nick Johnson followed with a potential double-play ball to short, but Everth Cabrera's toss to second baseman Luis Rodriguez was dropped, and both runners were safe. Two batters later, Adam Dunn ripped a go-ahead RBI single.

After Blanks' home run, which Riggleman said "took the wind out of our sails a bit," Dunn's longtime friend from his playing days in Cincinnati became the hero.

"For [Kearns] to come in and be ready in a big situation like that shows a lot," Dunn said. "That's the guy I've seen my entire career. I don't know what he did different, but he needs to bottle that one up."

Riggleman has frequently praised Kearns for the attitude the ninth-year veteran brings to the ballpark each day. Despite being the highest-paid player on the team, Kearns has not been an everyday starter since the first month of the season.

But he was mobbed on Sunday. As he rounded first base, the Nationals celebrated one of the rare positives in Kearns' trying season.

"I treat it the same way as if I was having a good year," Kearns said. "I don't look at it different. You've got to be the same person every day. You take the good with the bad. Hopefully you have more good, but if not, you keep on keepin' on."