Boston Celtics guard Isaiah Thomas has spent the bulk of his career answering doubts about a variety of issues, to the point where his first All-Star selection last February didn’t even silence the questions about his ability to serve as the top scorer on a legitimate playoff team. To a certain extent, these are just the kinds of doubts that follow a player who would be lucky to get measured at his listed height of 5-9. Thomas is certainly used to it all in his sixth NBA season.

If Thomas continues his current form, those ever-present concerns are likely to become a thing of the past. The Celtics star didn’t only come into Friday’s game at the Atlanta Hawks as the league’s fourth-leading scorer — he’s also been one of the best clutch scorers throughout this season.

[Join a Yahoo Daily Fantasy Basketball contest now | Free NBA Yahoo Cup entry]

Thomas added to that growing reputation in the fourth on Friday. The Celtics entered the final quarter up 78-65 but saw the Hawks draw to within 94-92 on a Mike Dunleavy three-pointer with 2:12 remaining. Thomas took over shortly thereafter, scoring five points on two possessions to put the Celtics up six in the final minute. However, the Hawks sandwiched his only miss of the last two minutes with two three-pointers to tie it up with only 25 seconds left.

To no one’s surprise, Thomas got the ball with a chance to avoid overtime. In keeping with his play over the last few weeks, he came through to give Boston the win:

Paul Millsap attempted a tough shot to tie at the buzzer, but he missed to give the Celtics the 103-101 win. Thomas finished with a mixed line — 28 points on 9-of-21 FG (including 5-of-13 from deep), nine assists, and five turnovers — but the story was what he did in the fourth quarter. He scored 13 of Boston’s 25 in the period, including seven in the final 80 seconds.

Yet the real story here is how those numbers are becoming normal for Thomas. In fact, his fourth-quarter scoring average is the best in at least 20 years:

When the Celtics need a fourth-quarter bucket, Thomas is the guy. He’s scored 24 in one fourth quarter and overtime, put up a franchise record 29 points in the fourth quarter a little more than a week later, and done much more damage over the course of the season. He’s the biggest reason why the Celtics hold the No. 3 spot in the East standings (just 1 1/2 back of the No. 2 Toronto Raptors) despite out-scoring opponents by only 2.3 points per game.

[Follow Ball Don’t Lie on social media: Twitter | Instagram | Facebook | Tumblr]

It’s enough to make Thomas a legitimate MVP candidate, if not yet a favorite. The questions over Thomas’s value won’t stop completely — it’s hard to hide a 5-9 player on defense in the playoffs — but there’s no longer much doubt that he’s very valuable. They call it winning time for a reason, and anyone who dominates those late minutes like Thomas deserves a great deal of attention.

– – – – – – –

Eric Freeman is a writer for Ball Don’t Lie on Yahoo Sports. Have a tip? Email him at efreeman_ysports@yahoo.com or follow him on Twitter!

Follow @FreemanEric