Watched closely by two and sometimes three defenders, Isela Rivera has had to find creative ways to keep the East Union offense moving forward this season.

On Thursday that meant working backwards — away from the goal.

Rivera broke the ice with a header in the 14th minute, but it was her ability to spring others that proved the difference in the Lancers’ 5-0 victory over Bear River in the opening round of the Sac-Joaquin Section Division IV tournament.

Rivera had two assists, each one coming with her back to the goal, as top-seeded East Union (17-0-1) returned to the semifinal round, the site of last year’s heartache.

The Lancers were seeded No. 1 a season ago, too, when Colfax ended their bid for the program’s first-ever section finals appearance with 2-1 victory at Dino Cunial Field.

This year’s roster may feature a handful of new names, a new coach and players in new positions, but the team holds an old grudge.

Rivera said East Union is driven by its past playoff failures. She and sister Isabella Rivera were not members of last year’s team, but each played for East Union in 2012.

“It’s been hard to go one-and-out or make it to the second round or lose in PKs,” Isela said. “We want to go all the way and make a statement for East Union.”

That didn’t bode well for Bear River (9-6-3), the runner-up from the Pioneer Valley League.

The Bruins were overmatched, overwhelmed and eventually outmanned in the loss. Bear River played the final 49 minutes with 10 players after a defender was sent off with red card for a hand ball.

She batted a ball of the goal line during wild sequence in front of the net, earning the ejection.

It mattered little in the end.

As it has done to nearly every opponent this season, East Union pinned Bear River in its own end, pelting goalie Jessie Cregar (11 saves) with shot after shot.

Isela finally broke through in the 14th minute with a header off of a cross from freshman sister Ilena Rivera.

Though she gives away considerable height to almost every defender that draws the assignment, the older Rivera uses her anticipation and will to win space — and most times, the ball.

“It comes down to how bad do you want to head it,” she said. “A lot of girls are afraid to head the ball. I love headers. I want to win every single ball that comes to me. I’ll jump, dive, crawl. I’ll do whatever I have to do to get the ball.”

Isela’s best work came with her back to the goal.

The San Jose State-bound striker sprung fellow senior Meghan Wallace with a nifty flick, splitting the defense with her pass.

Wallace controlled the ball, setting up a rocket shot with her right foot to make it 2-0. The goal was East Union’s second in 5-minute span.

Later, Isela linked up with junior sister Isabella Rivera on a give-and-go in the penalty area.

“I have a lot of attention on me all the time,” Isela said. “If I’ve got two or three players on me that means two or three of my teammates are open. So if they’re going to find me, I’m going to play it right back to them and they’re going to have the better shot.”

That much was true in opening minute of the second half.

Isabella slipped a pass to Isela who, with defenders on each hip, feinted like she would turn inside and set up her own right foot. Instead, she fed a streaking Isabella with a back-heel and let her finish with the right-footed blast.

“She’s the kind of player that can go anywhere on the field. She’s going to create her own space,” East Union coach Victor Polanco said. “They put two and three players on her, but she always creates the space.

“Playing with her back to the goal, it’s something that they like to do in practice too.”

Marissa King and Ilena also scored for the Lancers, who will host Liberty Ranch on Wednesday. Liberty Ranch defeated Center, 1-0, in their opening round game on Thursday evening.

Goalie Taylor Gray had one save in an uneventful start. Bear River’s first shot came in the 45th minute and its first shot on frame in the 64th on a long free kick.

Gray controlled it easily.

East Union outshot Bear River 21-1 and began substituting starters in the 30th minute.

“I was hoping for more pressure on my defense,” Polanco said. “I’m not sure who we play next, but whoever comes here, we’ll be ready.”