The second-half dominance that catapulted Jake Arrieta to last year's NL Cy Young Award carried over into the Chicago Cubs ace's first outing of 2016.
The intended anchors of a presumably improved Arizona Diamondbacks rotation, meanwhile, have yet to live up to their past performances.
Shelby Miller looks to improve after a rough Arizona debut Sunday when matched up against Arrieta in the finale of a four-game series.
While Chicago is meeting the expectations of a projected World Series contender during a 4-1 start, the Diamondbacks haven't shown much to justify the raised hopes brought on by several aggressive offseason moves by losing four of their first six games.
Arizona appeared especially improved in the pitching department following the additions of Miller and Zack Greinke, the runner-up to Arrieta for the 2015 Cy Young. However, its starters have a combined 8.07 ERA and allowed nine homers in 32 1-3 innings.
The Cubs scored three first-inning runs off Greinke en route to Saturday's 4-2 victory that helped put behind a difficult day before, when they blew a late lead in a 3-2 loss hours after learning that young slugger Kyle Schwarber suffered a season-ending knee injury in Thursday's series opener.
Greinke, whose 1.66 ERA with the Dodgers edged out Arrieta's 1.77 for tops in the majors last season, has surrendered 11 runs in 10 innings through two outings with Arizona.
''Too many mistakes, getting hit hard early and then started pitching better later. But not good enough so far,'' he said. ''I've got to start pitching better here on out.''
Miller's Diamondbacks debut was marred by one bad inning - a six-run fourth Tuesday against Colorado in which he was tagged for three homers among six hits. The 2015 All-Star did bounce back with two perfect innings before being let off the hook when Arizona scored nine unanswered runs to record an 11-6 win.
"I think the best thing that came out of it is after he gave up the six spot we needed those innings," manager Chip Hale told MLB's official website. "He went back out there and sucked it up and probably his last inning was his best."
Miller rarely had such offensive help during a deceiving 6-17 season with Atlanta last year, receiving the lowest run support in the majors. His 21 quality starts prompted Arizona to trade 2015 No. 1 overall pick Dansby Swanson and outfielder Ender Inciarte to the Braves for the 25-year-old's services.
Though Miller finished strong, he'll likely have to be better to hand Arrieta his first regular-season loss since July 25. The right-hander was 12-0 with a minuscule 0.53 ERA in 14 starts thereafter - highlighted by an Aug. 30 no-hitter against the Dodgers - to edge Greinke for the Cy Young.
Arrieta picked up right where he left off in Monday's opener, limiting the Angels to two singles and one walk over six splendid innings in a 9-0 victory. None of those three baserunners advanced past first.
"I expect to pitch this way every time I take the mound," he told MLB's official website. "Once the ball leaves your hand, you can't dictate the results. I expect to execute at a pretty high percentage."
Arrieta outdueled Miller in Atlanta on July 19, striking out 10 over seven scoreless innings in a 4-1 win.
Chicago's Ben Zobrist went 3 for 4 with an RBI on Saturday and is 8 for 20 thus far. Dexter Fowler is 10 for 19 with seven runs scored white hitting safely in all five games but is 0 for 8 against Miller.