COLUMBIA, Mo. -- Missouri came from behind twice, including a two-run rally in the 10th inning capped by freshman Trey Harris' walk-off single, to defeat No. 6 South Carolina 4-3 on Saturday at Taylor Stadium.

The win moves Mizzou to 18-5 on the year and 5-0 in SEC play as it sits atop the SEC East standings. The win is Mizzou's seventh one-run win, fourth walk-off and the Tigers improve to 5-0 when tied after eight innings this season.

Combined with Friday night's 3-2 win against the sixth-ranked Gamecocks, the Tigers have clinched the series. It is the first time since March 27-29 at Auburn last season that Mizzou has won a series against a ranked opponent. It is Mizzou's first series win against a top-10 team since May 16, 2008, when Mizzou swept fifth-ranked Nebraska.

Mizzou rode the pitching of freshman Tanner Houck, who was downright filthy outside of a four-hit, two-run second inning. He retired the final eight batters he saw, striking out the side in the eighth, keeping the Tigers in the game late. Houck finished the game, tossing a career-high 8.0 innings, walking none and striking out eight while scattering just eight hits.

Mizzou had just one hit heading into the sixth inning and finished the game with 14 as it scored once in the seventh, once in the eighth to tie the game and then twice in the 10th after South Carolina regained the lead in the top of the frame.

Closer Breckin Williamsearned his fourth win of the season after tossing 2.0 innings, allowing two hits, a run with three strikeouts and a walk. South Carolina's Taylor Widenar took the loss, dropping to 1-1 on the year.

But it was Harris who was the hero on Saturday. With Mizzou trailing 3-2 heading into the 10th inning, the Tigers rallied. Jake Ring roped his team-leading ninth double into the gap in left center to open the frame, ahead of a Ryan Howard single to put runners on the corners with one out.

Josh Lester then drove in Ring on a sacrifice fly to center. Brett Bond then popped up to short in front of a walk by Zach Lavy, setting the stage for Harris. On a 1-2 pitch, Harris bounced a ball back up the middle and into center field to score Howard from second base, sealing the win. Mizzou had three hits and a walk in the 10th inning.

South Carolina got on the board in the top of the second, using four hits -- two with two outs -- to score pair of runs of off Houck. Nine-hole hitter DC Arendas had the first RBI single, a bloop into left, and the next came from leadoff hitter Max Schrock, a liner into center.

Houck got stronger as the game went on, giving Mizzou a chance. The offense came alive in the bottom of the sixth, loading the bases with one out, but Howard bounced into a 6-4-3 double play to end the threat.

But Mizzou finally got to SC starter Jack Wynkoop in the seventh, putting runners on the corners with no outs after a perfectly-executed hit-and-run. Lavy then grounded into a 4-6 fielder's choice to score Lester.

Houck then struck out the side in the eighth and four of the final five batters he faced as his day ended after the eighth inning. Mizzou tied the game in the eighth inning on an RBI single by Howard. Lester nearly gave Mizzou the lead on a single into left field, but Gamecock left fielder Elliot Caldwell gunned Ring at the plate.

Williams then came on to pitch the ninth before allowing South Carolina to take the lead in the 10th. But he kept the lead at just 3-2 with some good pitching, setting the stage for Harris and the Tigers to walk off in the 10th.