The A’s went retro Tuesday night, turning the clock back offensively and delivering the kind of smack down that was a common place over the first half of the season.

They hammered out a season-high 20 hits and routed the Kansas City Royals 11-3 at Kauffman Stadium, and there were lots of reasons to smile for manager Bob Melvin as he scanned the box score.

Perhaps the most encouraging development for the A’s was watching their 3-4 hitters bust out. Josh Donaldson homered twice and had four RBI, and cleanup man Brandon Moss went 4-for-5 and drove in two runs.

It was the A’s highest scoring output since they plated 13 in a July 24 victory over Houston. They had averaged just six hits over their previous six games, but in another flashback to the early part of 2014, they got their offense cranking early on Tuesday night.

The A’s scored once in the first, twice in the third, once in the fourth and twice in the fifth to give Jon Lester (13-7) plenty of support. Consider it a good sign for Oakland’s offense that Lester – coming off a three-hit shutout -- wasn’t even a main storyline in this one.

The lefty did go six innings and extended his winning streak to seven games. He hasn’t lost since June 7.