In men golf, who won the U.S. Open championship in 2018?

Introduction / Context:
The U.S. Open is one of the four major championships in professional men golf and is organised by the United States Golf Association. Winning this event is a major achievement and becomes a key highlight in a golfer s career. This question asks who won the men U.S. Open in 2018, a year in which several well known players were in contention.

Given Data / Assumptions:

• The tournament is the U.S. Open golf championship.
• The year of interest is 2018.
• Options listed are Brooks Koepka, Tommy Fleetwood, T. Finau and D. Johnson.
• We assume the official U.S. Open results for that year.

Concept / Approach:
The concept required is familiarity with recent golf majors and their champions. Brooks Koepka had a period of dominance in the U.S. Open, winning it in consecutive years. In 2018 he successfully defended his title. Tommy Fleetwood, Tony Finau and Dustin Johnson are all highly ranked golfers who performed well, but they finished behind Koepka in that particular tournament.

Step-by-Step Solution:
Step 1: Recall that Brooks Koepka won the U.S. Open in 2017.Step 2: Remember that he repeated this success by winning the U.S. Open again in 2018, becoming a back to back champion.Step 3: Tommy Fleetwood posted a strong score but finished as runner up in 2018.Step 4: Dustin Johnson and Tony Finau were in the chasing group but did not win the event.Step 5: Therefore, the correct answer among the options is Brooks Koepka.

Verification / Alternative check:
Golf records and sports summaries from 2017 and 2018 highlight the fact that Brooks Koepka became the first player in many years to win consecutive U.S. Opens. Writer reviews of the championship often mention that Tommy Fleetwood made a strong final round charge but could not overtake Koepka. These recognitions confirm that Koepka was indeed the 2018 champion and not Fleetwood, Finau or Johnson.

Why Other Options Are Wrong:
Tommy Fleetwood is incorrect because he finished as runner up, despite an excellent closing round. Dustin Johnson has won other major tournaments and led at various stages in different U.S. Opens, but he did not win this particular edition. Tony Finau is a consistent high finisher but did not secure the 2018 U.S. Open title. Only Brooks Koepka combined the necessary scoring over four rounds to win the championship that year.

Common Pitfalls:
Learners who follow golf only casually might confuse the winner with the player who had the most talked about final round, such as Fleetwood, or they might remember Dustin Johnson s strong performances at U.S. Opens in general. Another source of confusion is mixing up the U.S. Open golf championship with the tennis U.S. Open, which is a different sport and has different champions. Keeping in mind that this question is about men golf and that Brooks Koepka won the U.S. Open in both 2017 and 2018 helps to avoid such mistakes.

Final Answer:
Brooks Koepka won the men U.S. Open golf championship in 2018.