The Chicago Cubs, refusing to sit back and savor last year’s World Series championship, opened the second half by jump-starting the trade deadline Thursday with a deal that stunned the baseball industry.

The Cubs acquired ace Jose Quintana from their rival Chicago White Sox for four prospects, including prized outfielder Eloy Jimenez and emerging right-hander Dylan Cease. They also received infielders Matt Rose and Bryant Flete.

The Cubs, who needed a jolt from their first-half doldrums, got the pitcher they needed to not only give them a chance to catch the Milwaukee Brewers in the NL Central, but afford them a shot to defend their World Series title.

It may turn out to be the boldest move any team makes before the July 31 non-waivers trade deadline, executed by the gutsiest executive in the game to pull it off.

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Cubs president Theo Epstein was determined to find a young, controllable pitcher, who can not only help them down this pennant stretch, but also the next few years. They recently tried to pry All-Star Michael Fulmer away from the Detroit Tigers, but the Tigers had no interest, unless they perhaps were willing to trade infielders Javy Baez and Ian Happ.

The cost was steep for the Cubs, however, in a rare deal between the two Chicago franchises.

Jimenez, 20, was among the last of the Cubs’ blue-chip prospects and although he lacked dominant power or speed to pair with his excellent hitting ability, he was ranked No. 5 in Baseball America’s midseason top 100 rankings. Jimenez, who participated in the Futures Game on Sunday in Miami, produced an .841 OPS at high-Class A Myrtle Beach (S.C.) in the first half and is a lifetime .293 batter despite consistently being several years younger than the competition in his league.

The bigger prize for the White Sox might be Cease. The right-hander, 21, has a career strikeout rate of 12.3 per nine innings in the minor leagues, and has struck out 74 in 51 innings this season at Class A South Bend (Ind.). He ranked 83rd on Baseball America’s updated top 100.

This trade enables the Cubs to keep their young nucleus intact by trading only prospects, and adds to the White Sox’s collection that gives them nine of the top 100 prospects in baseball, according to MLB.com. Cease is yet another power arm who consistently hits the upper 90-mph mark, and he joins a stable of prospects such as Michael Kopech and Lucas Giolito who give the White Sox a decent chance to develop a dominant rotation.

The Cubs, who badly were looking for a controllable pitcher with Jake Arrieta and John Lackey eligible for free agency in a season, struck gold with Quintana, 28. He has a career 50-54 record and 3.51 ERA, but has been yielding a 2.70 ERA since the end of May.

Perhaps of greater import, Quintana will make just $8.85 million in 2018, with reasonable club options of $10.5 million and $11.5 million for 2019-2020.

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