Colin Linder blasted a solo home run to right-center field to walk Lambert off against Denmark on Wednesday, 5-4.
Linder's game-winner came in the bottom of the seventh inning against Denmark reliever Harry Harris and gave the Longhorns sole possession of first place heading into the final stretch of the regular season.
Braden Bamburowski struck out eight batters across 4 2/3 innings, giving up three runs on two hits and walking seven. Jonny Smith collected the win in relief, tossing two innings and giving up one unearned run and striking out two.
Lambert struck first in the bottom of the second inning, when Smith's RBI single scored Daniel Carlson.
Denmark responded with a two-run fourth, which began with a Connor McGinn walk and Teddy Davenport RBI double. Jake Myers plated Davenport three batters later with an RBI single. McGinn drew three walks in the game.
Lambert tied the game 2-2 with another RBI single by Smith, which scored Linder. Smith led the Longhorns at the plate, finishing 3-for-3 with four RBIs.
Francesco Capocci drew a bases-loaded walk in the fifth inning to give the Danes a one-run lead, but back-to-back errors in the bottom of the frame allowed Lambert to go up 4-3.
JJ Corr bounced into a double play with runners on the corners in the sixth, but Nic Ferrer scored on the play to knot the game 4-4.
Linder homered on the third pitch of the seventh inning to send Lambert's dugout into a frenzy.
Lambert (17-10, 10-5 Region 6-7A) will travel to West Forsyth at 6:15 p.m. Friday, while Denmark (11-14, 8-6 Region 6-7A) will host North Forsyth at 6:15 p.m. Friday.