After 14 years at Lyon, Lacazette decided it was time to move on and was reported to have agreed to join up with his France team-mate Antoine Griezmann at Atletico Madrid.
However, Atletico then had a transfer ban upheld over the signing of foreign minors and with the Madrid club barred from registering new players until January 2018, Arsenal stepped in.
Arsenal's fans have been crying out for a top-rank striker ever since Robin van Persie was sold to Manchester United in 2012 and in Lacazette their wish appears to have been granted.
A dead-eyed finisher, the 26-year-old was the top-scoring Frenchman in each of the last three Ligue 1 seasons and left Lyon having scored 113 goals in his last four campaigns.
He cost Arsenal an initial fee of £46.5 million ($60.6 million, 51.6 million euros), making him both Arsenal's biggest ever signing and Lyon's biggest ever sale.
Lacazette will form a potentially devastating attacking trident with Mesut Ozil and Alexis Sanchez, but manager Arsene Wenger has warned that he will need time to find his feet in north London.
"Sometimes it takes a few months, sometimes it takes very little time," Wenger said.
"The only thing I must say with Lacazette is that week after week, he looks to adapt quickly. But overall I think it will take him one or two months."
Morata's move to England was no surprise, but the Spain international had been earmarked for a move to Manchester United.
Instead, United hijacked Chelsea's attempt to bring Romelu Lukaku back to Stamford Bridge and the champions switched their attentions to Morata.
The 24-year-old cost Chelsea £58 million and is due to take the place of Diego Costa, who -- completing the love triangle -- is at loggerheads with the club over his desire to return to Atletico.
- Hazard out -
Morata has scored in a Champions League final, netting for Juventus in their 2015 loss to Barcelona, but arrives after a frustrating season as a back-up player at Real Madrid.
Tottenham Hotspur manager Mauricio Pochettino has claimed Morata was deterred from joining Spurs two years ago due to his fears about the competition he would face from Harry Kane.
But despite the striker's inability to dislodge Karim Benzema from the Madrid starting XI, Chelsea manager Antonio Conte believes he can reach the very top.
"He is a young player and my task is to help him improve and exploit his quality," said the Italian.
"I know he has great quality to become one of the best strikers in the world."
Sunday's game, the traditional curtain-raiser to the English season, is a repeat of last season's FA Cup final.
Having streaked to the title, Conte was seeking to emulate his compatriot Carlo Ancelotti by winning a league and FA Cup Double in his first maiden Chelsea season.
But Arsenal blew Chelsea away with a sensational display, Aaron Ramsey's 79th-minute winner securing a 2-1 win that brought the beleaguered Wenger a record seventh success in the competition.
Sanchez could start on the bench for Arsenal, having only returned to training on Tuesday after being given an extended break following his exertions with Chile at the Confederations Cup in Russia.
Centre-back Shkodran Mustafi, likewise, is short of fitness, after also playing at the tournament, while defender Gabriel and midfield pair Francis Coquelin and Jack Wilshere are definitely out.
With Costa frozen out and Eden Hazard absent due to a broken ankle, Conte could try out a new-look strike-force of Morata and Michy Batshuayi.
New recruit Tiemoue Bakayoko, formerly of Monaco, has a knee injury, but Victor Moses could play as the suspension incurred by his dismissal in the FA Cup final does not apply in Sunday's game.
source: news.abs-cbn.com
