TEMPE, Ariz. -- Ace Jered Weaver breezed through three scoreless innings and the Angels, with most of their everyday players in the lineup, tallied 13 runs in the first four innings of a 15-3 win over the Cubs at Tempe Diablo Stadium on Friday.

Mike Trout hit a grand slam and drove in five runs, Chris Iannetta fell three feet shy of a two-homer day, J.B. Shuck had a three-run triple and the Angels notched two crooked-number innings, scoring four runs off Chris Rusin in the second and nine runs against James McDonald and Jonathan Sanchez in the fourth. Jett Bandy added a two-run homer in the eighth off Frank Batista.

"We were pleasantly surprised this afternoon how many pitches we were on," Angels manager Mike Scioscia said, "and it could be a function of those guys hitting more live BP earlier. We were on pitches that you don't always expect in your first Spring Training game."

The Angels are pushing their players harder than ever this spring, after going a combined 15 games below .500 in their last two Aprils and posting the worst ERA in baseball last spring.

In tune with that, seven starting position players -- all except Josh Hamilton, who's out at least two weeks with a strained left calf -- were in the lineup and played defense for five innings. And Weaver went three full innings in a Cactus League opener for the first time in his career, giving up just one infield hit, striking out one, walking none and allowing only one hard-hit ball all afternoon.

Rusin, 27, is competing for the fifth spot of the Cubs' rotation after coming up from Triple-A and pitching well last season, with a 3.93 ERA in 66 1/3 innings. In his first Cactus League start, though, Rusin was charged with four runs on five hits and a walk, striking out two.

"I remember facing him last year, and he did well against us in San Diego," Cubs manager Rick Renteria said prior to the game, referencing an Aug. 25 game when Rusin threw 6 1/3 scoreless innings against the Padres. "He's a guy who is certainly in the mix."

The Cubs got on the board in the fourth, when light-hitting second baseman Darwin Barney -- one of only three everyday players in the lineup, along with Ryan Sweeney and Nate Schierholtz -- lofted a solo homer to left field off left-hander Brian Moran, a Rule 5 pick who's trying to lock down a bullpen spot. Top prospect Kris Bryant also homered for the Cubs, knocking a two-run shot in the seventh off Jarrett Grube.

Iannetta got the Angels on the board with a two-run double off the left-center-field wall in the second, with Erick Aybar and Trout following up with line-drive RBI singles. In the fourth, Iannetta led off with a homer and McDonald put the next three batters on for Trout. The 22-year-old outfielder then got a 2-0, low-and-in fastball and laced it way out to left field, over the grassy picnic area that sits beyond the fence.

"Mike's got such a short swing," Scioscia said. "You wouldn't think it would take him that many at-bats to get him where he needs to be. It took him one, I guess."

Up next: The Cubs will be busy on Saturday with a day-night, home-road doubleheader. Travis Wood will start the early game in Mesa at Cubs Park against the Giants at 2:05 p.m. CT, while Edwin Jackson is scheduled to pitch the night game against the Diamondbacks in Scottsdale at 8:10 p.m. CT. Jackson is hoping to rebound from last season, when he led the National League with 18 losses. The second game will feature top prospects Bryant and Jorge Soler in the lineup. Both are among the so-called "core four" of highly-touted players. Both games will be available on an exclusive webcast on Cubs.com.