It was Notre Dame versus Rutgers when Jeff Samardzija was on the mound against Todd Frazier on Saturday.

Score one for the New Jersey school.

Samardzija allowed a tiebreaking homer to Frazier and the Chicago Cubs lost 5-3 against the Cincinnati Reds in the opener of a day-night doubleheader.

Alfonso Soriano hit a two-run drive in the first for Chicago, which has lost six of eight. Soriano's 22nd homer of the year gave him 1,000 career RBIs.

But Xavier Paul hit a tying two-run shot in the second and Frazier gave the Reds the lead for good when he led off the fourth with a drive to the first row of the second deck in left for his 17th homer and third in four games. He also had a two-run shot Friday night that gave the Reds a 4-3 lead, and the NL Central leaders went on to win 7-3.

"I played against Frazier in college," said Samardzija, who also played football for Notre Dame. "He's confident. He feeds off momentum and he's swinging a hot bat. Maybe he can put on a Rutgers jersey and I can put on the Irish jersey and we can go back to college. I'm sure I'll be facing him a lot in the future."

Frazier also drove in Jay Bruce with a sacrifice fly in the eighth inning. He went 2 for 3 and is batting .600 (15 for 25) with three homers and 11 RBIs in 10 games against the Cubs this season.

"I don't know what it is," said Frazier, a leading contender for NL Rookie of the Year. "It's crazy. I'm comfortable against them and confident, like always. When I'm at the plate, I feel like I can some damage."

Samardzija (8-11) gave up four runs and six hits in five innings. He struck out five, walked none, hit a batter and threw a wild pitch.

The right-hander is 1-3 with a 4.07 ERA in four starts this month.

The Cubs are keeping an eye on the young starter, who is up to 144 2-3 innings after reaching 88 last year.

"Samardzija had OK stuff," manager Dale Sveum said. "He had 85 pitches in five innings and I pushed him pretty hard his last couple times out. He gave up home runs on a hanging split and a hanging slider."

In cozy Great American Ball Park, it doesn't take much to hit the ball out.

"Their lineup was unforgiving, not the ballpark," Samardzija said. "I made some good pitches but I have to keep the ball out of the middle of the plate with two strikes."

Miguel Cairo also hit his first homer of the season as the Reds roughed up another Chicago starting pitcher for three home runs. They hit three off Travis Wood on Friday night and three more off Samardzija.

Cueto (16-6) improved to 11-0 with a 1.62 ERA in 13 day games this season. He gave up three hits and struck out eight in eight innings, earning a standing ovation when he walked off the mound for the last time. He also hit David DeJesus, the first batter of the game.

Cueto, who didn't allow a runner past first base after the first inning and retired 19 of the last 20 batters he faced, is the first Cincinnati pitcher since Danny Jackson in 1988 to win 16 of his first 25 starts. Cueto has won seven of his last eight appearances to move into a tie with Tampa Bay's David Price for the major league lead in wins.

Aroldis Chapman allowed two hits, a walk and a run — his first in 24 appearances — but held on for his 29th save.

The first-place Reds (73-47) began the day with a six-game lead over Pittsburgh and an eight-game advantage over St. Louis.

Soriano drove a 3-2 pitch 433 feet into the second deck in left field with two outs in the first. He is one of six players with 1,000 career RBIs, 350 home runs, 400 doubles and 250 stolen bases.

"That puts him in some good company," Sveum said. "It put us up with our best pitcher on the mound."

Cairo belted a one-out shot to left on a 1-2 pitch in the fourth for his first homer since Sept. 21 against Houston, making it 4-2.

Samardzija believes he can pitch 200 innings and feels good in spite of this setback.

"I feel awesome. I'm as strong as I've ever been. I believe I can pitch 200 innings," Samardzija said. "I don't know if they'll let me. They have my best interests in mind. It's not up to me. I just want to finish strong."

NOTES: The Cubs are working on a new contract for SS Starlin Castro, but general manager Theo Epstein said nothing has been finalized yet. ... Both teams recalled pitchers from their Triple-A affiliates to start the second game of the doubleheader. The Cubs promoted LHP Brooks Raley from Iowa, while the Reds recalled RHP Todd Redmond from Louisville for his major league debut. ... Neither team was required to send anybody out to make room. Major League Baseball rules allow teams to add a 26th player to their active roster for doubleheaders such as Saturday's, which was scheduled after a May 1 postponement. ... Soriano joined Barry Bonds, Andre Dawson, Willie Mays, Alex Rodriguez and Gary Sheffield as the only major league players with at least 1,000 RBIs, 400 doubles, 350 home runs and 250 stolen bases in their careers.