Roger Federer saw off the challenge of resurgent fellow Swiss Stan Wawrinka to reach the semi-finals of the Cincinnati Masters on Friday.
Federer has won all seven of the finals he has appeared in at the ATP Masters 1000 event in Ohio, and is on course to triumph for the first time as a 37-year-old, having come from behind to beat Wawrinka 6-7 (2-7) 7-6 (8-6) 6-2 after two hours and 19 minutes.
It was stern test of Wawrinka's progress in recovering from long-term knee trouble, and he passed with flying colours, until fatigue crept up on the three-time grand slam winner.
Federer, meanwhile, advances to a semi-final against David Goffin, with Novak Djokovic or Marin Cilic awaiting in the final.
Both players could have been forgiven for being somewhat below their best late on Friday at the Lindner Family Tennis Center, having been required to finish their third-round matches earlier in the day due to bad weather interrupting Thursday's schedule.
Wawrinka had beaten Marton Fucsovics in straight sets, while Federer overcome Leonardo Mayer, also in two.
There was little indication they were feeling the residual effects of those exertions, though, as the first set remained on serve.
With both players near their consistent best, Wawrinka saved two break points in the sixth game, while Federer offered his compatriot none.
The older man looked poised to take the opener when he was presented with two break-point and set-point opportunities in the 12th game, but Wawrinka dug deep to save the first with a forehand down the line, before staving off the other by coming to the net and forcing Federer to send a forehand passing shot long.
Unexpectedly, the resulting tie-break rapidly got away from Federer, who netted a routine overhead and made another poor forehand error to allow Wawrinka to take it with ease.
The second set proved a similar affair, but this time it was Wawrinka's turn to blink in the tie-break, as he immediately gave up a mini break to fall behind. And when the 33-year-old's attempted backhand down the line sailed wide, the match was level at 1-1.
Wawrinka eventually ran out of energy in the third set, giving up his serve for the first time in the sixth game when he came to the net and could not get enough of his racquet on a Federer passing shot.
And from there, the senior partner in the iconic Swiss duo pulled clear in imperious fashion, consolidating and then breaking again to love to take it on the first of three match points, when Wawrinka sent a forehand long.
|Cahill considering Chelsea departure in January|
|Kaepernick to receive Harvard´s highest honour in African, African-American studies|
|Defending champion Ostapenko dumped out of Korea Open|
|Mourinho is an inspiration - Nuno|
|Witty Wilson ´delighted´ to be praised for Fisher heroics while sitting on couch|
|Burns, Denly and Stone in England squad for Sri Lanka Tests|
|Aspas reveals interest from Real Madrid, Atletico|
|Arsenal´s Mkhitaryan a doubt for Everton match|
|Klopp demands Liverpool ´stay angry´ against Southampton|
|Long-serving Tabarez signs four-year Uruguay extension|
|Injured Mendy ruled out of Cardiff trip|
|Douglas Costa out up to a month with ankle & thigh injuries|
|Slater shrugs off Feki hit amid Grand Final suspension concerns|
|Crisis? What crisis? Klopp unconcerned by Salah form|
|I didn´t convince him, he decided for himself - Guardiola says thanks to Aguero|
|Leno frustrated by Arsenal bench role|
|Joshua almost 2st heavier than Povetkin for Wembley bout|
|From salvation to the record books - Fisher revels in European Tour´s first 59|
|Lahm says Germany best for Euro 2024 as UEFA publishes report|
|Lopetegui backs Modric over Ronaldo for individual prizes|
|Goretzka to start against former club Schalke, confirms Kovac|
|Fisher shoots first 59 in European Tour history|
|Simeone defends Ronaldo after controversial Champions League red|
|Slater sees Storm into Grand Final, awaits fate over ´shoulder charge´|
|Hogg to miss Scotland´s November Tests following ankle surgery|
|Osaka through as Azarenka and Garcia crash out|
|Burgess weighing up legal options after being cleared in Rabbitohs investigation|
|Uncapped Cottrell and Gordon named in Wallabies squad|
|He´s done fantastic work - Mourinho hails Wolves boss Nuno|
|Joshua v Povetkin: No need for fireworks on AJ´s Wembley return|
|Six titles, 204 goals - Aguero´s incredible City career in Opta stats|
|Read to miss Argentina clash, Ioane brothers sign new deals|
|Pedro allays injury fears after Europa League clash|
|Dilly dilly to all the Cleveland fans! Mayfield promises further Browns success|
|Manchester United ´hell´ left Zaha depressed|
|Jackson hesitates in naming Mayfield as Browns´ starting QB|
|LeBron congratulates Browns for ending 635-day winless streak|
|Aguero Extension: 10 of the best goals from the Manchester City star|
|Aguero signs City contract extension until 2021|
|Stress from drink-driving charge may have contributed to Lloris injury – Pochettino|
|CBF backs Cruzeiro´s Dede appeal and suggests VAR investigation|
|The big Friday Premier League quiz|
|Red Sox clinch AL East with win over Yankees|
|Brighton star Knockaert reveals battle with depression|
|Bud Light beer fridges open after Browns snap 19-game winless streak|
|Browns end 635-day drought with first win since 2016 after downing Jets|
|Blue Jays overturn 8-2 deficit in improbable ninth-inning comeback|
|Colo Colo 0 Palmeiras 2: Scolari´s men poised for Libertadores SFs|
|Tour Championship would enhance successful year, says Tiger|
|Pogba: Man United getting better after winning run|
|What bothers me is that he has time to even do that – LeBron responds to Trump tweet|
|Cowboys most valuable NFL team for 12th successive year|
|Mkhitaryan aiming for glory with Europa specialist Emery|
|Sarri: Pedro´s injury is not too serious|
|This Week in U.S. Sports: Drama in Minnesota, a Judge returns and tragedy in Iowa|
|Tottenham will overcome rough patch – Lamela|
|Torreira impresses for Arsenal but leaves with knock|
|Gattuso urges Higuain to be less predictable with his movement|
|Steelers´ Brown: ´Obviously I don´t want to be traded´|
|Woods, Fowler share Tour Championship lead|
|LeBron James backs Serena Williams after US Open controversy|
|Thiem into St Petersburg quarters, but retiring Youzhny bows out|
|Wigan clinch home semi-final with win over Huddersfield|
|Can apologises following sexism accusations|
|De Bruyne expects to be back for Manchester derby|
|Celtic 1 Rosenborg 0: Griffiths late show lifts Hoops|
|Woods eagles 18 to make 65 at Tour Championship|
|Arsenal 4 Vorskla 2: Aubameyang at the double in entertaining triumph|
|Dudelange 0 AC Milan 1: Deflected Higuain goal spares Gattuso´s blushes|
|Birthday boy Rashid inspires Afghanistan to Asia Cup win|