Novak Djokovic sauntered to a long-awaited victory in the first round of the Monte Carlo Masters and Jared Donaldson was involved in a confrontation with the umpire during his loss to Albert Ramos-Vinolas on Monday.
Djokovic had not won a match since the Australian Open back in January, but took only 56 minutes to knock out fellow Serbian Dusan Lajovic 6-0 6-1 in his opening encounter of the clay-court season.
Kei Nishikori came from a set down to oust 12th seed Tomas Berdych 4-6 6-2 6-1, while Milos Raonic also lost the opening set before seeing off wildcard Lucas Catarina.
Spanish duo Roberto Bautista Agut and Ramos-Vinolas made it through, the latter's victory somewhat overshadowed by Donaldson losing his cool with Arnaud Gabas.
Berdych was the only seed to bow out on day two of the tournament in the Principality.
DJOKOVIC SWAGGER RETURNS
Former world number one Djokovic has had a year to forget so far, suffering shock losses to Taro Daniel and Benoit Paire in Indian Wells and Miami respectively after recovering from elbow surgery.
The 12-time grand slam champion was a shadow of his former self in those defeats in the United States, but looked very much at home in his first match of the year on the red surface.
He lost just three points on serve in the first set and returned superbly, showing no mercy on his compatriot in a one-sided encounter watched by a crowd of 10,200.
Djokovic, with coach Marian Vajda back in his corner following his split with Andre Agassi and Radek Stepanek, will face Borna Coric in round two.
DONALDSON SEES RED
American Donaldson saw the red mist as he was consigned to defeat by Ramos-Vinolas.
The unseeded American could be hit in the pocket after a furious rant at Gabas during the second set of his 6-3 6-3 loss.
To say Donaldson was unimpressed with Gabas not calling a Ramos-Vinolas serve out would be an understatement, as he confronted the French official before calling for a supervisor.
A ranting Donaldson pointed at Gabas and shouted "show me the mark" before claiming "you're making up a mark because you don't like me."
NISHIKORI DIGS DEEP TO TOPPLE BERDYCH
Like Djokovic, Nishikori is also finding his feet after a lengthy spell out due to injury but a win over Berdych should serve as a big confidence boost.
Nishikori, down to 36 in the rankings, received on-court treatment for a sore wrist but battled his way into round two in his first appearance in the tournament for six years.
"It's actually great to come back this tournament," said the 28-year-old from Japan. "I haven't got a lot of matches this year. I hope I can play more matches on clay.
"I always enjoy this European season... I feel like Tomas was struggling a little bit in second, and third too. Nobody's expecting 100 per cent in the first couple of matches."
|Kohli: India were better and deserved to win|
|Bears shut down Goff, Rams|
|India survive dramatic finish against Australia|
|Klopp calls for electric Anfield atmosphere against Napoli|
|Saints clinch back-to-back NFC South titles, Bears trump Rams|
|Bucks improve to 2-0 against Raptors with win in Toronto|
|Black Caps include Patel for Sri Lanka Tests|
|Maidana: River want Real Madrid clash|
|Cowboys top Eagles in OT behind stellar Cooper display|
|AC Milan evaluating Fabregas signing – Leonardo|
|WATCH: Steelers´ chance at game-tying field goal slips away|
|Hayne will plead not guilty to charges, says lawyer|
|Boca boss Schelotto: The only thing I feel is sadness|
|Cardinals´ Fitzgerald makes NFL history with most receptions for one team|
|River Plate´s Copa Libertadores star Gonzalo Martinez confirms January departure|
|Klopp: I was never worried about Salah´s form|
|Packers QB Rodgers sets NFL record for most passes without an interception|
|World Cup bulking hampered Man United form – Lukaku|
|Leonardo rules out Ibrahimovic Milan return|
|Warriors´ Green to return against Timberwolves|
|I feel for him… we´ll make it work – Butler responds to Embiid´s frustration|
|Torino draw no missed opportunity for misfiring AC Milan, claims Gattuso|
|We´ll always be linked together forever - Wade reflects on playing with James before final match-up|
|O´Sullivan wins record seventh UK title|
|Chiefs secure playoff berth, Saints win NFC South|
|River Plate 3 Boca Juniors 1 (aet, 5-3 agg): Quintero and Martinez clinch Libertadores title in extr|
|WATCH: Chiefs QB Mahomes throws no-look pass|
|Dolphins defeat Patriots on miraculous final play|
|Kizzire eagle snatches QBE Shootout victory|
|AC Milan 0 Torino 0: Donnarumma shines, Cutrone misses late chance|
|Back to the drawing board for West Indies - Chase|
|Copa Libertadores: Messi and Griezmann among stars in Madrid for River-Boca Superclasico|
|Brady sets NFL record for most career TD passes|
|Copa Libertadores: Tevez named on Boca bench for Superclasico final|
|Premier League needs VAR, right now! - Benitez fumes over Dean´s decisions|
|McCall expects Itoje to fit for the Six Nations|
|Solari salutes Real Madrid character after ´ugly´ Huesca win|
|Berbatov defends under-fire Lukaku|
|Sarries crush Blues to maintain unbeaten start|
|Newcastle United 1 Wolves 2: Doherty punishes Yedlin red with late winner|
|Deeney jokes he´ll ´smash´ former Watford star Richarlison|
|Huesca 0 Real Madrid 1: Bale ends drought as Solari´s men edge to victory|
|Ponting: Umpires not looking at no-balls|
|Bale ends longest LaLiga goal drought|
|Porter backs Brees for MVP, Saints for Super Bowl|
|Verstappen eyeing 2019 title fight|
|Wall ´shouldn´t have played´ against Cavaliers after scoring just one point|
|Hazard: Man City the best team in the Premier League despite Chelsea win|
|LeBron explains why he gave a Grizzlies employee his game-worn shoes|
|Bangladesh cruise to ODI victory as seamers punish Windies|
|Football will win over violence, claims CONMEBOL president|
|Alcorcon support Reus Deportiu over unpaid players|
|Saponara explains cheeky celebration after last-gasp leveller|
|Godin and Filipe Luis return to Atletico training|
|Kick It Out condemns alleged racist abuse of Sterling|
|Emotional Oosthuizen clinches South African Open title|
|The Sunday Seven - 7 Key Opta facts for NFL Week 14|
|Martino salutes Atlanta´s grand plan|
|India´s tail must show greater application - Bangar|
|Mourinho: Diogo Dalot can be new Gary Neville|
|Sterling hits out at media coverage of black players|
|Lyon roars with defiance as Australia aim for unlikely victory|
|Bulls coach Boylen: Hooked starters ´embarrassing´ in record loss|
|Martinez pays tribute to Martino, Almiron after MLS Cup glory|
|LeBron: Final Wade matchup will be bittersweet|
|Alvarez-Kovalev rematch set for February 2|
|Newcastle Jets 2 Brisbane Roar 0: Sheppard, Jair score first A-League goals|
|India close in on victory in first Test|
|LeBron flirts with triple-double as Lakers down Grizzlies|
|Lomachenko unifies WBO, WBA titles with win over Pedraza|