There are very few similarities between Daniil Medvedev and Grigor Dimitrov.

Medvedev is the world No 5 who reached the finals of the last three hard-court tournaments in North America and won the title at Cincinnati. Dimitrov is the world No 78 who lost seven of his last eight matches before the US Open and starting his hard-court season this year with a loss against world No 405.

Dimitrov, perhaps the most talented of the lost generation, fell from world No 3 in 2017. Medvedev, perhaps the least unexpected of the Next Gen to make the Grand Slam breakthrough, is at a career-high rank.

The 23-year-old Russian is in the middle of his best season with an ATP Tour-leading 49 wins while the 28-year-old Bulgarian was enduring a miserable season with a 12-15 record before US Open.

Medvedev played “ugly” in his own words to overcome a quadriceps injury and beat 2016 champion Stan Wawrinka 7-6 (6), 6-3, 3-6, 6-1. Dimitrov played his largely beautiful game – that had once earned him the moniker ‘baby Fed’ – to beat five-time champion Roger Federer 3-6, 6-4, 3-6, 6-4, 6-2.

The glaring differences and contrasting routes to get here, notwithstanding, the two will meet in an unexpected semi-final with their first Grand Slam final apperance on line.

Medvedev outlasts physical battle

Medvedev has been a lot of things this US Open: dark horse, genuine challenger, bad-behaved brat, villain. But absorbing boos from the crowd and the blows Wawrinka is capable of raining down, he proved that he is also a terrific tennis player.

With a mix of clever strategy and versatile tennis, he stood up to adversity in a manner few players of his generation have. The 23-year-old has played 21 singles matches in the last four weeks, having reached the finals of Washington Open, Rogers Cup and Cincinnati and it was evident that he was gassed out.

In the first set, he needed a medical time out, taped his leg and took a painkiller and even considered quitting the match. But the way in which he won the tiebreak – he led 5-2, lost the next four points and took the last three in style – gave him a new lease of life and he utilised it by killing Wawrinka’s rhythm.

When he couldn’t shoot bullets from the baseline as he does, he started mixing up the ammunition in his trunk. He recalibrated his shots and started to throw a mix of drop shots, lobs, varied his pace, length and placement and rarely gave his opponent any chance to build a point. He played a solid and smart game even after Wawrinka had taken the third set to ensure that he didn’t need a decider.

The leg may have bothered him at the start, but by the end of the match he was standing firm with a stunning performance.

Also read: In Wawrinka and Dimitrov’s quarter-final run, a throwback that goes beyond the Big Three

Dimitrov outlasts mental battle

In contrast, for Dimitrov, it was a case of his opponent not being 100% fit. The Bulgarian said he figured by the time he won the second set that Federer was struggling and sensed an opportunity to win his first match against the 38-year-old.

But the Swiss’ injury can’t take away from what has been a sensational resurgence from the ATP Finals champion. It was a close game, make no mistake. Dimitrov won 139 points, Federer 135 with five more winners. But Federer made 66 unforced errors – to his opponent’s 41 – just short of the 77 in the shock loss to John Millman last year.

Even beating a less-than-100% Federer in five sets is not an easy task. A lesser player may have caved in after the third set was gone thanks to his own errors – the ever-problematic doubles faults on break points. But even at world No 78, this was still Dimitrov. He stayed in the match and attacked with the flair that we are used to seeing from the man on the other side of the net.

His strongest moment came in the seventh game of the fourth set, which could have changed everything. He had broken Federer to start the set and had kept up the aggression in an attempt to push for a second break. But the veteran survived a 12-minute long seventh game with eight deuces and seven break points.

Too often in the past this would be the moment which would result in the Dimitrov express losing steam and heading towards derailment. It almost seemed like it had, as the Bulgarian was down break points five times in the final game but held to serve out the fourth set and all but shut the door on Federer.

After the Swiss taking a medical timeout before the fifth, the set was a mere formality and the Bulgarian raced to a win.

Once the heir apparent to the big three, Dimitrov has all-round game: His serve is sharp, his one-handed backhand powerful and he is probably among the most agile players of his time. But his mentality was the biggest concern and his erratic games and frequent losses seemed to finally push even his own team away as mentor Andre Agassi and coach Radek Stepanek didn’t even come to New York.

But this win will give him belief as he takes on the hottest player this season for a place in his first ever Grand Slam final.

An intriguing semi-final awaits

Dimitrov is the lowest-ranked US Open semi-finalist since Jimmy Connors (174th) in 1991 while Medvedev is the youngest US Open semi-finalist since Novak Djokovic in 2010. One is playing his best tennis in years while the other is still young enough to not know what his best tennis is.

First-time Major semi-finalist, Medvedev, has won two titles in 2019, including an ATP Masters where he beat Djokovic. The Bulgarian, who has reached this stage twice before at 2014 Wimbledon and 2017 Australian Open – has reached just one quarter-final back in January.

Will Dimitrov have just the little extra stamina against the worn-down Russian or will the big stage get to him? Will Medvedev show that he has yet another gear to hit or will the toil of August take a toll on his body?

Either way, we can be assured of an intriguing first men’s singles semi-final at the US Open.