Not since January 2008 had Andy Murray rallied to win after losing a 6-1 first set on a hard court.  Nor had he reached a semifinal since his historic breakthrough at Wimbledon last summer.  Both of those streaks ended on Thursday night in Acapulco, when Murray notched a strange but notable three-set victory over Gilles Simon.

Victory looked far from plausible during the early stages of the match as the reigning Wimbledon champion dropped six of his first eight service games.  Not an aggressive shot-maker, Simon still found the courage to attack Murray’s vulnerable second serve.  He pounded that weakness through the first set and a half, building a 6-1 4-2 lead.  But Murray also heightened the pressure on the Frenchman’s serve as the second set progressed, ultimately breaking at love when Simon served for the match.

Not deterred by that missed opportunity, the underdog claimed an early lead in the second-set tiebreak.  Murray again needed to unleash his most seamless court coverage and competitive resilience to grind through a series of endless rallies from the baseline.  Both men prefer to outmaneuver their opponents rather than crush massive first strikes, so a war of attrition developed.

Once Murray turned the tide in the second-set tiebreak, he would have felt confident that he could win that war.  Simon, who had incurred a leg injury in Australia, summoned the trainer in the second set and faded sharply in the third.  He won fewer than half of his service points in the final set and could not convert the two break points that Murray’s ongoing service struggles offered him.

Able to fend off the Frenchman’s fierce resistance, Murray achieved the main goal for which he likely entered Acapulco.  He needs as much live match action as possible to regain his rhythm after back surgery, and Simon’s steady style of play should have helped him find that rhythm.  Murray also should have felt encouraged by his durability during the 1-6 7-6(4) 6-2 comeback.  He had not impressed in that area last month but normally counts it among his strengths.

While the second-seeded Murray survived to reach the semifinals, top seed David Ferrer could not.  In a mirror image to Murray’s quarterfinal, Ferrer won the first set of his quarterfinal comfortably.  Then, an injury to his left leg overtook him early in the second set.  With two Masters 1000 tournaments on the horizon in March, Ferrer wisely decided that discretion was the better part of valor and withdrew from the match. 

The Spaniard’s retirement sent the lanky Kevin Anderson into a semifinal against someone who just solved another tower of power.  Conquering the serve of Ivo Karlovic on Thursday, the loose-limbed Alexandr Dolgopolov will seek to reach ATP finals in consecutive weeks for the first time when he faces Anderson.  But so will Anderson, who finished runner-up in Delray Beach last Sunday as Dolgopolov finished runner-up in Rio.  An entertaining contrast should emerge between the programmatic Anderson and the improvisational Dolgopolov.

Both of those Acapulco semifinalists deserve credit for building on their February surges as another man in their position saw his momentum surge end.  Ernests Gulbis squared off with Grigor Dimitrov for the first time in an uneven but dramatic quarterfinal.  This foretaste of what could become a key ATP rivalry opened with four service breaks, featured 19 double faults, and hung very much in the balance until the last point.  Each man had chances to put away his opponent before Dimitrov prevailed 7-5 in the third set.  Gulbis stood three points from a 6-4 6-4 victory, while his eventual conqueror squandered a 4-2 lead in the final set.

A breakthrough quarterfinalist at the Australian Open, Dimitrov flirted with winning sets from Murray in two hard-court matches last year.  He also has won sets from Nadal in three different matches since the start of 2013, and he upset then-world No. 1 Novak Djokovic at the Madrid Masters 1000 tournament.  If Murray cannot avoid the tepid lulls that have defined his week so far, Dimitrov will have the opportunity to deliver another statement win.