More than a few pundits boldly claimed that the Miami Heat would upset the Milwaukee Bucks in the second round of the playoffs. Well, those people are probably feeling pretty good after the Heat earned a 115-104 Game 1 victory over the Bucks behind 40 points from Jimmy Butler and 27 points from Goran Dragic. Bam Adebayo added 12 points, 17 rebounds, and six assists in the win.

The Heat hype train is quickly filling to capacity, and their impressive showing on Monday only proves that they are indeed capable of upsetting the Bucks in this series. Let's not jump the gun here, though. The Heat were undeniably imposing in Game 1, but let's not forget that this is the league-best Milwaukee Bucks we're talking about here. They are still the favorite to come out of this second-round matchup, and that's thanks in large part to one overly compelling reason: Giannis Antetokounmpo.

Be that as it may, there are a number of key factors that we can take away from Miami's Game 1 victory over Milwaukee.

1. Giannis' Kryptonite?

Antetokounmpo — the newly crowned Defensive Player of the Year winner and soon-to-be back-to-back MVP title holder (a feat that has been achieved only by Michael Jordan and Hakeem Olajuwon) — was relatively MIA in Game 1. His numbers were still pretty impressive, with the Bucks star just missing out on another triple-double with 18 points, 10 rebounds, and nine assists, but there's also no denying that the Heat did quite a number on Giannis on this one.

After averaging 30.6 points on 59.0 percent shooting in the first round against the Orlando Magic, Antetokounmpo came back down to earth against the Heat in Game 1. He scored just 18 points on 6-of-12 shooting, which notably is the least field goal attempts he has taken in this year's playoffs. Credit has to be given to Miami's outstanding defense, which never really allowed Giannis to get going in this one. They stifled him all night long, with Jae Crowder, Bam Adebayo, Andre Iguodala, and Jimmy Butler all taking turns on the MVP, plus terrific team defense forming a wall against his drives.

Giannis Antetokounmpo, Bucks, Heat

It's easy to mark this off as an off night for Giannis, who himself went 4-of-12 from the charity stripe on the evening, but it has to be said that this is not the first time this season that the Heat have successfully contained him. When these two teams met in March, the Bucks held Antetokounmpo to just 13 points, which resulted in a 16-point blowout victory in favor of Miami.

Have the Heat found the key in stopping one of the most dominant players of all time? Probably not. However, they seem to have the ability to prevent him from an offensive explosion, and at the end of the day, that might just be all they need to cause a series upset.

2. Jimmy Buckets

Giannis' poor showing was key in Miami's win, but there's no denying that Jimmy Butler's playoff career-high 40-point performance was the big difference between these two sides in Game 1.

Butler has been tremendous in the playoffs thus far. His mid-range game has been on point, and this was on full display again on Monday versus the Bucks. Butler has also found his shot from distance, going 2-for-2 in Game 1. In five games in the postseason, the 6-foot-7 swingman has been draining triples at a very impressive 66.7 percent clip (1.2 makes per game). The Heat are one of the best 3-point shooting teams in the league, but Butler didn't shoot well from deep in the regular season. If he's hitting jumpers consistently, that makes Miami even more dangerous.

Jimmy Butler, Heat

Perhaps overshadowed by his offensive outburst is how Butler's tenacity on defense was another key factor in his team's Game 1 win. He was his dominant self on the defensive end yet again, setting the tone for Miami's defense all night long.

If Butler is able to keep this up — even with some allowance for a bit of a fall off — then he should give Miami a very good chance of advancing to the Eastern Conference Finals. Perhaps Giannis should think about guarding him. 

3. Beatable Bucks

Last but not least, what Miami was able to prove on Monday is that the Bucks are beatable. Their Game 1 loss to the Orlando Magic was considered as a one-off, especially considering how they handily won the next four games.

However, Monday's defeat just shows how Milwaukee is not as invincible as others might presume. The Bucks may have been the most dominant force in the regular season, but all that has to be thrown out of the window come playoff time.

Giannis Antetokounmpo, Khris Middleton, Brook Lopez, Bucks

Make no mistake about it: the Bucks are still the favorite here. As a matter of fact, they could win the next four contests, and even that wouldn't be all that surprising.

Nonetheless, it is clear that the Heat are going to be an extremely tough test for Milwaukee. Many considered this team to be the worst matchup for the Bucks, and if Game 1 is any indication of how this series will play out, then Milwaukee might just be heading home much earlier than originally anticipated.

Getting Eric Bledsoe back from a hamstring injury to put more pressure on Miami's defense would be helpful. Furthermore, Bucks head coach Mike Budenholzer has some adjustments to make, including thinking of shortening his rotation and playing his best players heavier minutes.