Minnesota United head coach Eric Ramsay put a lot of preparation into the chance that penalty kicks could decide matches in the MLS Cup Playoff series against Real Salt Lake. He even invited front-office staff to Blaine on Monday to make it inhospitable for players as they practiced PKs on their own training ground. The employees booed, chanted, gestured and otherwise tried to distract the Loons from behind the goals. While it wasn’t the unfriendly confines of America First Field in Sandy, Utah come Tuesday, the prep was still worth it as MNUFC and RSL went to penalties after a scoreless 90 minutes. For all his planning, Ramsay still had to turn it over to at least five players. After one player missed on each team, it went to a sixth round and landed on unlikely taker for MNUFC: center back Jefferson Diaz. But the Colombian went down the middle, rippled the net and putting pressure on Salt Lake. RSL midfielder Braian Ojeda hit the crossbar, sealing United’s 5-4 win. The Loons captured Game 1 of a first-round series and can advance to the conference semifinals with a win in Game 2 at Allianz Field at 8 p.m. Saturday. Game 3, if necessary, would be Nov. 8 in Utah. “It’s easy to say in hindsight, but I didn’t doubt Jefferson in that situation,” Ramsay said. “He’s a very cool customer, very level-headed. … He has taken everything in stride since he has been here. Quiet. Serious. Gets on with it. Confident. He was probably just the man for that job.” Before Diaz, it was more conventional takers in Tani Oluwaseyi, Sang Bin Jeong, Wil Trapp and Kelvin Yeboah. Those midfielders and strikers converted their kicks, but Loons captain center back Michael Boxall and RSL veteran Justen Glad both failed to convert in the third round. Boxall’s low shot to the right was denied by Zac MacMath. Glad’s shot was sent over the crossbar, leaving Dayne St. Clair with nothing to do but watch it sail deep into the stands. The Loons’ win looms for Salt Lake. Last year was the first with best-of-three series in the opening round and all eight teams that won Game 1 advanced to the next round. Third-seeded Real Salt Lake and sixth seed MNUFC also played to a 0-0 draw in Utah on Oct. 2 and 1-1 in St. Paul on April 6, but a winner was needed Tuesday. In the 68th minute, Ramsay brought in two of the three players who shifted the 4-1 win over St. Louis on Oct. 19: Oluwaseyi and Jeong, who scored two goals 10 days ago. They came in for Robin Lod and Joaquin Pereyra, which also removed two likely PK takers. Three minutes later, Oluwaseyi had a shot, aided by Yeboah’s toe-poke pass, but MacMath’s right arm denied the quality scoring chance. Yeboah and Bongi Hlongwane each had scoring chances denied by MacMath in back-to-back fashion in the 82nd minute. St. Clair made his own fair share of saves, including one on Cristian Arango in the 92nd minute. And St. Clair double save on Arango and Diego Luna in the 51st minute. In the first half, the Loons allowed Salt Lake more possession but limited avenues to attack in the middle of the field. RSL had only one shot on goal in the opening 45 minutes, and that was after a poor Wil Trapp giveaway in MNUFC’s defensive third. St. Clair’s left leg denied Luna’s shot in the 12th minute.