Lavrentiy Borisov was born in 1909.

He graduated from flight school in Odessa in 1933.

Starshiy leitenant Borisov took part in the Soviet-Finnish Winter War between November 1939 and March 1940, flying Polikarpov I-15bis in 5 IAP-KBF.

On 7 February 1940, he was decorated with the Order of the Red Banner.

Borisov was later deputy commander of the 96 Otdelnaya Aviaeskadrilya (OIAE - independent squadron). The commanding officer of this unit was kapitan Aleksandr Korobitzin. In June 1941, the unit was based on Izmail airfield and equipped three Polikarpov I-153s and fourteen Polikarpov I-15bis.

During the Axis attack on Soviet Union in June 1941 Rumanian forces attacked the part of the front that included Izmail.

At 14:00 on 22 June 1941, fourteen I-15bis and three I-153s of 96 OIAE (the entire squadron) scrambled from their airfield at Izmail, alarmed by early warning on incoming enemy aircraft- They attacked eight Romanian I.A.R. 37 biplanes of Escadrila 18 bombardament at 1,000 meters over Izmail, close to the estuary of the Danube in southern Bessarabia, claiming five of them shoot down.
The 96 OIAE commander kapitan Alexandr Korobitzin and starshiy leitenant Mikhail Maksimov (whose victim fell into the Danube River) each claimed a destroyed. A third was claimed by mladshiy leitenant Boris Maslov from starshiy leitenant Maksimov’s flight. One shared was claimed by starshiy leitenant Borisov, deputy commander of 96 OIAE, and leitenant Nikolai Cherkasov. The fifth, finally, was claimed as a shared between leitenant Vasilii Kuroedov (flight commander), leitenant Leonid Khomutov, leitenant Alexandr Evstigneev and leitenant Shota Gogmachadze.
In fact, only one I.A.R. 37 was shot down by Soviet fighters, most probably by mladshiy leitenant Maslov while a second was claimed by the 463rd Anti-Aircraft Battery under starshiy leitenant G. Okhota. Maslov returned to base much later than his colleagues on his last drops of fuel. He had pursued an enemy aircraft way behind the line of the Danube until finishing it off deep inside enemy territory. Upon return, ground crew could count many bullet holes in the airframe of Maslov’s I-15bis.
The Rumanian biplanes, which lost two of their numbers, had been escorted by eight He 112B from Grupul 5 Vânatoare.

He was decorated with a second Order of the Red Banner on 13 August 1941.

Borisov left 96 OIAE in February 1942, when he was posted to 11 IAP-KBF.
He remained with this unit for a very sort time before being posted to 71 IAP-KBF in March 1942.

In November 1942, he was posted to 4 GIAP-KBF.

On 7 February 1943, he was decorated with the Order of the Patriotic War 1st Class.

Borisov was taken off operations on 30 August 1943 and later worked in training units of the Navy.

On 28 December 1944, he was decorated with the Order of the Red Star.

Borisov ended the war with 1 biplane victory and a total of 2.
These had been claimed during 406 combat missions and a 30 air combats (as of 31 January 1943).

On 30 August 1945, he was decorated with the Order of the Patriotic War 2nd Class.

He was decorated with a second Order of the Red Star on 10 November 1945 and a third Order of the Red Banner on 15 November 1950.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1941
	22/06/41	14:00	1/2	I.A.R. 37 (a)	Shared destroyed	I-15bis (b)		Izmail area	96 OIAE
	1942
1	06/06/42	night	1	Ju 88	Destroyed	I-153			71 IAP-KBF
	06/06/42	night	1/3	He 111	Shared destroyed	I-153		Kotlin area	71 IAP-KBF
	1943
2	10/06/43	night	1	Ju 88	Destroyed	La-5			4 GIAP-KBF

Biplane victories: 1 and 2 shared destroyed.
TOTAL: 2 and 2 shared destroyed.
(a) Claimed in combat with I.A.R. 37s from Escadrila 18 bombardament, which lost 2 aircraft (1 to AA fire). 96 OIAE claimed 5 destroyed without losses.
(b) These victories may have been claimed while flying I-15bis or I-153s.

Sources:
All aces of Stalin 1936-1953 – Mikhail Bykov, 2014
From Barbarossa to Odessa: Volume 1 – Dénes Bernád, Dmitriy Karlenko and Jean-Louis Roba, 2007 Ian Allan Publishing Ltd, ISBN 978-85780-273-3
Heinkel He 112 in action - Dénes Bernád, 1996 Squadron/Signal Publications, Carrollton kindly provided by Ondrej Repka
Morskie letchiki v oborone Odessy - A.P. Dorokhov, 1982 Mayak, Odessa, kindly provided by Yuri Shakhov
Rumanian Air Force: The Prime Decade, 1938-1947 - Dénes Bernád, 1999 Squadron/Signal Publications, Carrollton, ISBN 0-89747-402-3
Sovetskaya aviacia nad morem - Sergey Bogatyrev, 1999 Aviacia i Vremya 3/99, Ukraine kindly provided by Ondrej Repka
Soviet Aces 1936-1953
Soviet Fighter Pilots 1936-1953 - Mikhail Bykov
Vtorzhenye, part III - Dmitriy Khazanov, 1996 Aviacia i Vremya 5/96, Ukraine kindly provided by Ondrej Repka
Additional information kindly provided by Mirek Wawrzynski