Weekend in Sport: Federer comes up short in Melbourne; Lacazette leads dominant Arsenal over Chelsea; Mayweather-Pacquiao II mooted

As the opening major of the calendar heats up, it's increasingly likely this is the year that their dominance wanes -- in another next gen triumph, 21-year old American Frances Tiafoe played the match of his nascent career to oust 20th seed Grigor Dimitrov 7-5, 7-6(6), 6-7(1), 7-5 to secure his spot in the quarter-finals.

But elder statesman Novac Djokovic, who has only dropped one set on his way to the final thus far, is showing no signs of slowing down.

The Serb, top-seeded in Melbourne, meets 22-year-old Daniil Medvedev in the Round of 16 Monday. Squeaking into the top 20, the young Russian hasn't faced any real opposition thus far in Melbourne, but will need to outdo Tsitsipas' giant-killing Sunday to knock the serial winning Djokovic off his perch.

LA Rams head coach Sean McVay was a callow teen the last time the Rams made it to football's biggest game. But now -- in part due to a shocking refereeing decision -- he has the chance to bring the title back to a town which went two decades without an NFL team.

Despite never leading in regulation, the Rams' Greg Zuerlein hit a 57-yard field goal in overtime to advance to Super Bowl LIII with a 26-23 win. With the score tied 20-20 as regulation ticked away, what appeared to be a clear pass interference violation occured when Rams cornerback Nickell Robey-Coleman appeared to plow into Saints receiver Tommylee Lewis, making helmet-to-helmet contact, but no flag was thrown.

ESPN reported that Saints coach Sean Payton said he received a call from the league's head of officials telling him that the ref had "blown the call." Payton said the admission was "hard to swallow."

Sunday's other conference championship clash -- between New England and Kansas City -- also went to extra time, ending 37-31 after the Pats' offense overpowered the Chiefs after a thrilling back-and-forth game.

The result means that the Boston team will contest its ninth Super Bowl since 2002, when the team -- featuring a young second-year QB by the name of Tom Brady -- beat the then-St. Louis Rams 20-17.

The Patriots join the Buffalo Bills (1990-1993) and Miami Dolphins (1971-1973) as the third team to appear in three consecutive Super Bowls.

Arsenal enjoyed a much-needed win against London rivals Chelsea on Saturday, winning 2-0 to match victories from Manchester City and United, Liverpool and Spurs. The North London team have improved against top-six teams this year under manager Unai Emery, and the Basque had stressed the importance of keeping pace with the leading pack ahead of the match.

Arsenal's French No. 9 Alexandre Lacazette was a huge part of the win, scoring the opener after 14 minutes and maintaining a harrying, tireless presence throughout. His efforts keep the Gunners in sight of fourth place and Champions League football next term.

But will Lac be there to enjoy it? Despite his obvious value to the team, he's only started 15 times this season, and is brought off early regularly -- something that would frustrate any professional. Following his substitution Saturday, in the 68th minute, a tweet from an account purporting to be his agent asked (rough translation): "Is this substitution the one that's too much?" adding the hashtag #ByeBye.

Arsenal's roster woes are well documented -- Aaron Ramsey Juventus-bound at the end of the season; Mesut Özil a forlorn, peripheral figure under Emery, and the manager restricted to a reported loan-only policy this transfer window -- so any suggestion that one of their main attacking players, who's scored eight goals despite those limited minutes, would be disastrous.

Mikaela Shiffrin continued her march toward greatness with a super-G win in Cortina on Sunday -- her 54th career World Cup win -- but fellow American Lindsey Vonn failed to finish what is likely to be her last competitive outing on the Italian course.

Embarking on her farewell season with injuries having taken a toll on her body, she made her comeback from injury by racing with braces on both knees.

Though it was a Sunday to forget for the skier with a record 12 wins in Cortina, she was in podium contention until midway, when she clipped a gate and veered off course. She finished 15th and ninth in the downhills on Friday and Saturday.

Vonn, arguably the greatest female skier in history, has 82 career victories and needs five more wins on the World Cup circuit to beat Ingemar Stenmark's record of 86, but with plans to retire in December she may run out of races.

Could we see another installment of boxing's most interminable rivalry?

It certainly looked like a possibility after an elated Manny Pacquiao took apart American Adrien Broner in a 12-round unanimous victory Saturday, and the Filipino legend bullishly suggested another matchup with Floyd Mayweather.

"My message is I'm still active, and if (Mayweather) goes back to the ring and wants to challenge me, I'm a champion. Get back to the ring and we will fight again if he wants," Pacquiao said after the fight in Vegas, where he sailed to victory, 117-111, 116-112 and 116-112.

Mayweather, whose last two fights have been against non-boxers -- UFC's Conor McGregor and a 140-second New Year's Eve exhibition pummeling of Japanese kickboxer Tenshin Nasukawa -- was watching from the sidelines as his old rival proved that there's life in his gloves yet.

After that New Year's exhibition his camp poured cold water on a reunion with the PacMan. Mayweather Promotions' Leonard Ellerbe told reporters the American "had no interest" in fighting Pacquiao.

Despite the potential interest -- and financial incentive -- it sounds like the right call. The two fighters are both in their fifth decade now -- Pacquiao turned 40 in December, and Mayweather will celebrate his 42nd birthday next month.

Long considered the fighters of their generation and despite a long-running animus, they've only fought once -- 2015's record-grossing "Fight of the Century," which went for the American -- and it was past both boxers' prime. Would a rematch prove anything?