CHICAGO -- The Chicago Cubs clubbed five home runs, including one by starting pitcher Jon Lester, as they scored early and often in a 16-4 victory over the Arizona Diamondbacks on Tuesday night in the series opener at Wrigley Field.

Anthony Rizzo homered twice, and Ian Happ and Javier Baez each had one homer as the Cubs matched a season high for homers in a game.

Lester hit his first major league homer -- a two-run shot to left field in the third inning.

He also fanned pinch hitter Jack Reinheimer in the fourth inning for the 2,000th strikeout of his career.

However, Lester didn't get the win, departing after four-plus innings and 104 pitches. The Cubs led 8-2 with one run in and runners on second and third and no outs.

Cubs reliever Hector Rondon (3-1) claimed the victory instead after he stepped in for Lester and worked 1 2/3 innings, allowing one hit and striking out one.

Losing pitcher Patrick Corbin (8-10) lasted just three innings as the Cubs hit him for eight runs (seven earned) on 10 hits.

The victory was the Cubs' third straight, sixth in seven games and 14th since the All-Star break.

Rizzo led the Cubs' 17-hit parade, going 3-for-5 with three RBIs and three runs. Happ, Willson Contreras, Addison Russell, Lester and Ben Zobrist had two hits apiece.

A.J. Pollock, Adam Rosales and Paul Goldschmidt each had two of the Diamondbacks' eight hits. Rosales was making his Arizona debut.

The Cubs already had a comfortable 8-3 lead after 5 1/2 innings before adding seven more runs in the sixth. The key blows were a two-run double by Contreras and Baez's three-run homer, his 14th home run of the season. Both came off Diamondbacks reliever TJ McFarland, who then departed.

Rizzo's second homer of the night, his 26th of the season, came in the bottom of the seventh for the 16th run, a Cubs season high.

Rosales singled home Jeff Mathis for the final run in the Arizona ninth off Cubs reliever Mike Montgomery.

Corbin loaded the bases in the first, and Albert Almora Jr. lined a single up the middle to bring home Zobrist and Kris Bryant for a 2-0 lead with one out.

The Cubs scored four times in the second, starting with Happ's leadoff home run. Happ sent Corbin's 3-2 pitch to left for his 14th homer of the season and a 3-0 lead.

Lester then reached on a single, advanced to third on an error on Zobrist's subsequent grounder and scored on Bryant's sacrifice to make it 4-0. Rizzo brought home Bryant with his 25th home run of the season, a one-out shot to left for a 6-0 lead.

Arizona got one back in the third. Pollock doubled to right with one out and scored on Paul Goldschmidt's RBI single to shallow center.

Lester made it 8-1 with in the third with his first career home run, a two-out shot to left on a 2-2 pitch that also drove in Happ.

Lester ran into trouble as he passed 100 pitches in the fifth. Rondon allowed another run charged to Lester, who yielded three runs and five hits in four-plus innings. He walked three and fanned nine.

Reinheimer struck out in his major league debut.

NOTES: The Diamondbacks recalled INF Jack Reinheimer from Triple-A Reno and optioned RHP Silvino Bracho to Reno. RHP David Hernandez and INF Adam Rosales, both acquired in trades, reported and were active for the game. ... Arizona also signed veteran OF Emilio Bonifacio to a minor league contract. ... The Diamondbacks send RHP Zack Godley (4-4, 3.06 ERA) against Cubs RHP Jake Arrieta (10-7, 4.03) in Wednesday's middle game. ... The Cubs made several moves in the wake of Monday's trade deadline, officially adding LHP Justin Wilson and C Alex Avila to the 25-man roster after they were acquired from the Detroit Tigers. In corresponding roster moves, RHP Justin Grimm and C Victor Caratini were optioned to Triple-A Iowa. ... The Cubs are the first defending World Series champions to be in first place on Aug. 1 since the San Francisco Giants topped the National League West to begin August 2011.