PULLMAN – Ian Sagdal blasted his second and third home runs of the season for Washington State but a slew of errors cost the Cougars, who fell to Washington 5-2 on Saturday. WSU (17-17, 5-10 Pac-12) still came away with its first series win over the Huskies since 2011, thanks to wins on Thursday and Friday, and has won five of its last seven games. Each of the two losses in that span, against No. 12 California last week and against the Huskies (19-14, 6-9) on Saturday, came when the Cougars were trying to put the finishing touches on a Pac-12 sweep. “I’ve played some really good teams in this conference and there are some teams that don’t let up on Game 3 and the teams that don’t let up are the ones that win Pac-12 championships,” coach Donnie Marbut said. “That’s what we want to be.” With the exception of Sagdal at second base, the Cougars start an entirely freshman infield. That inexperience hadn’t caused too many growing pains in the field for the Cougars, but on Saturday some youthful mistakes cost the Cougars a shot at the sweep. “I think their expectations of themselves were lower than what we have for them. They’re great infielders,” Sagdal said. “Shane Matheny is one of the best third basemen we’ve been since I’ve been here. Jack Strunc, same thing. They’ve got to have high expectations for themselves.” The Cougars committed five errors on Saturday, including three in the decisive seventh inning. Washington’s Jack Meggs, the son of head coach Lindsay Meggs, led off the inning with a single, and advanced when Matheny dropped a fielder’s choice off the bat of Matt Jackson. Chris Baker plated them both with a double down the left-field line and advanced to third. The Cougars brought in their infield and Braden Bishop slapped a two-out single over the left side to score Baker. After Sagdal’s solo blasts in the first and fourth innings gave the Cougars a 2-1 lead, a throwing error by Strunc scored Joey Morgan after a Baker single. “We let up a little bit and you can’t let up against anybody, let alone your rival,” Marbut said. “The UW is a heck of a team, it’s not like they were going to show up today and roll over and they played extremely hard.” The win went to Troy Rallings (2-1), who threw four innings of scoreless relief for the Huskies. The Cougars will take a break from Pac-12 play next week, hosting New Mexico State on Monday, then play a four-game home series against San Jose State that opens on Thursday.