This year’s AFC Championship Game will be a rematch of one of the most thrilling games of the 2018 regular season — a 43-40 New England Patriots victory over the Kansas City Chiefs at Gillette Stadium in Week 6.

In anticipation of Sunday’s matchup, we rewatched that game to see what lessons could be gleaned from both teams’ performances. Some observations:

TALE OF TWO HALVES

The Chiefs wound up hanging 40 on the Patriots, so it’s easy to forget New England’s defense actually had the upper hand for the first 30 minutes.

Using some creative pass-rush and coverage schemes (including precursors to the “amoeba” look they’d debut in earnest weeks later), the Patriots succeeded in confusing quarterback and potential NFL MVP Patrick Mahomes in the early going. Mahomes threw one interception to linebacker Dont’a Hightower in the first quarter and another to safety Duron Harmon in the end zone late in the second.

The Chiefs managed just three field goals in the first half despite driving inside New England’s 25-yard line on four of their five possessions and trailed 24-9 at the half.

“We played the first half literally the exact way we wanted to,” Hightower said Tuesday. “We were able to mix things up, keep those guys guessing and keep them on their toes, not letting those guys make big plays.”

Of course, things quickly changed after halftime. Mahomes, who’d misfired on three potential touchdowns in the first half, scrambled out of the pocket and hit since-released running back Kareem Hunt for a 67-yard score just three plays into the third quarter, and the Chiefs went field goal, touchdown, touchdown on their next three drives.

After a Chiefs punt — the only one by either team in the game — and a Patriots field goal, Mahomes immediately hooked up with wide receiver Tyreek Hill for a 75-yard touchdown pass that tied the game at 40 apiece with three minutes remaining.

The Patriots escaped with a victory after Rob Gronkowski hauled in a 39-yard bomb from Tom Brady to set up Stephen Gostkowski’s game-winning 28-yard field goal as time expired.

Mahomes’ second-half line: 9 of 13 for 188 yards and four touchdowns with no interceptions. His deep touchdown strikes to Hunt and Hill were the two longest plays the Patriots’ defense has allowed this season.

Taking away the big play has to be at the top of New England’s to-do list on Sunday.

“You give (Chiefs coach) Andy Reid any kind of time, and he’s able to draw up a couple things,” Hightower said. “Something that we learned in the second half was that we’ve got to play a full 60. He was able to draw up a couple plays and make a couple big plays and score at the end.”

TYREEK HILL

Like the Chiefs’ offense as a whole, Hill broke out in the second half after being held in check for much of the first.

In the opening 29 minutes, the electric wideout had just one catch on four targets for 2 yards. In the final 31, he had six catches on eight targets for 140 yards and three touchdowns.

Stopping Hill, who also had another 75-yard touchdown catch when the Patriots and Chiefs met in 2017, will be the absolute No. 1 priority for New England’s secondary, and you can expect a different approach this time around.

Cornerback Jason McCourty was the man primarily responsible for Hill in Week 6, with Jonathan Jones, Eric Rowe or a safety picking him up when he shifted into the slot. (Devin McCourty was in coverage on two of Hill’s three touchdowns. He outran Duron Harmon on the other.)

Stephon Gilmore, the Patriots’ All-Pro top corner, mostly shadowed Sammy Watkins, holding the taller Chiefs receiver to two catches on four targets for 18 yards.

Since Jason McCourty hasn’t been the most consistent player in coverage this season (he had a rough game in the divisional round), it would be in the Patriots’ best interest to have either Gilmore or rookie J.C. Jackson cover Hill, who’s widely considered the fastest player in the NFL.

Jackson, who still has yet to allow his first NFL touchdown pass, could play a pivotal role in this game. He actually was a healthy scratch in Week 6 before beginning to see consistent playing time the following week.

Devin McCourty and fellow safety Patrick Chung were solid in covering Kansas City’s Travis Kelce, holding the elite tight end to five catches on nine targets for 61 yards and no touchdowns.

CHIEFS RUNNING BACKS

The Patriots surely are thankful they won’t need to deal with Hunt, who racked up a whopping 431 yards from scrimmage and four touchdowns in these teams’ last two meetings. Damien Williams has proven to be a more-than-serviceable replacement, though, surpassing 100 rushing yards twice in four games since replacing Spencer Ware as the Chiefs’ feature back.

One thing Williams might not be able to replicate, however, is Hunt’s explosive receiving ability.

Before he was cut in early December after a video of him kicking and pushing a woman went public, Hunt was averaging 14.5 yards per reception. He had six catches for 105 yards and a touchdown against the Patriots and would have had another if Mahomes hadn’t overthrown him on this play:

Williams has been a moderately productive pass-catcher throughout his career, but he’s averaging a modest 7.0 yards per catch on 23 receptions this season.

PATRIOTS PASSING GAME

Brady threw for 340 yards and posted a 109.2 passer rating against a Chiefs defensive backfield that’s changed significantly over the last three months.

Safety Ron Parker, who played every defensive snap in the game, was waived Tuesday. Safety Josh Shaw, who surrendered the aforementioned deep ball to Gronkowski, was gone by the end of November. Starting cornerback Orlando Scandrick was benched last month and replaced by undrafted rookie Charvarius Ward, who played only on special teams in Week 6.

The Chiefs also have safeties Daniel Sorensen and Eric Murray back from injury and could have the services of three-time All-Pro Eric Berry, who recently suffered a setback in his return from a torn Achilles and didn’t play in the divisional round.

Brady’s receiving corps also looks different nowadays. Josh Gordon (nine targets, five catches, 42 yards) is suspended indefinitely, and Phillip Dorsett, who was not targeted in the first Chiefs game, has seen an uptick in usage in recent weeks.

The Patriots’ offensive line kept Brady upright for the majority of the night, surrendering two sacks, one QB hit and just nine total pressures against a Chiefs team that tied for the NFL lead in sacks during the regular season. One of the sacks resulted in a fumble, however, on what might have been the 41-year-old quarterback’s worst play of the season.

Kansas City will have star edge rusher Justin Houston available Sunday. He didn’t play in Week 6.

SONY MICHEL

The Chiefs have one of the NFL’s worst run defenses, and Michel took full advantage, gaining 7 or more yards on seven of his 24 carries to finish with 102 and two touchdowns. The Patriots as a team totaled 176 rushing yards, with guards Joe Thuney and Shaq Mason, fullback James Develin and Gronkowski all excelling as run blockers.

SPECIAL TEAMS

The Chiefs only had to travel 3 yards on their second-to-last touchdown drive. That’s because return man Tremon Smith returned the preceding kickoff 97 yards, continuing a trend of uncharacteristically horrific kick and punt coverage by the Patriots during the first half of the season.

“All I remember from going back to my notes from when we played Kansas City was writing down that we’re not very good in the kicking game,” Patriots special teams captain Matthew Slater said Tuesday. “I saw that today, and I certainly haven’t forgotten how we played against these guys. It was terrible, so we’re going to try and avoid a repeat of that. I think that we’ve certainly made strides throughout the course of the season.”

Slater went on to note how the midseason additions of Albert McClellan and Ramon Humber have energized the team’s coverage units. The Patriots allowed 24.6 yards per kickoff return during the regular season (26th in the NFL) but 20.4 over their last five games.