Brandon Belt’s three-run double in the seventh inning propelled Coppell to a 4-1 victory over McKinney Saturday night, forcing a third and final game in the Texas Collegiate League championship series.  Belt’s two-out flyball hooked toward the rightfield line, out of the reach of Marshal outfielder Zach Chamberlin, clearing the bases and breaking a 1-1 tie.The loss snapped an eight-game winning streak in TCL playoff games for McKinney. The Marshals are now 3-1 in the 2007 playoffs after running the table to go 5-0 en route to the 2006 championship.The Copperheads’ big inning began as designated hitter Jeff Nutt lead off the top of the seventh with a sharp single off the glove of third baseman Tyler Hohman. The hit prompted Marshal coach Kyle Hope to bring in reliever Mike Lee in place of starter Jonathan Runnels. Tyler Goolsby, who had entered the game as a defensive replacement at catcher one inning earlier, dropped a well-executed sacrifice bunt to move Nutt to second base, followed by Pat McCrory’s comebacker to the mound that sent Nutt to third base.Lee then issued back-to-back walks to Sean Jones and Jonas Fester, the no. 1 and 2 hitters in the Coppell lineup. Belt, the keystone of the Copperhead offense during the playoffs, then delivered his double. Belt attempted to move to third as Chamberlin made a strong throw rightfield to almost catch Fester at the plate, but a perfect relay from catcher Bryan Holaday to Hohman retired Belt. Belt, who will transfer from San Jacinto College to the University of Texas for the 2008 season, now has six rbi in the playoffs while going 5-for-13, with the double and two home runs.Garrett Clyde earned the win, working two perfect frames in relief of Coppell starter Lucus Engle. Engle permitted a leadoff walk to Trae Williams in the bottom of the first. Williams stole second and then scored on a soft one-out single to center field by Brandon Glover.  Glover is now 3-for-3 with runners in scoring position in his combined opportunities in the Hornsby Division series and the championship series.Coppell tied the game in the top of the fifth as Nutt established his pattern for the night of leading off innings with singles and then moving to second on a sacrifice bunt, this one by Mikey Horn. McCrory pushed a bunt toward first base, forcing Derek Wiley off the bag to make the play. Wiley picked up the ball and made his throw as McCrory and second baseman Williams arrived at the bag together. Both runner and defender went down in a collision and the ball went to the fence, allowing Nutt to score easily.Kyle Walker notched a three-up, three-down eighth before Jake McCarter earned the save by retiring the Marshals in order in the ninth.The deciding game is scheduled for a 7:05 p.m. start Sunday at Coppell’s Snake Pit at the Coppell ISD sports complex. The TCL championship title comes down to a final third game for the third time in the league’s four-year history. Coppell took the first TCL title over Graham, 5-4, in 2004. McKinney fell to Denton, 3-1, in the 2005 winner-take-all-game.